"They're both daddy's girls - real little tomboys. The thought that they are growing up on the other side of the world and that we'll miss all those moments during their childhood . . . well, it's very sad. For our son, of course, but for us, too. This has been harder than we ever could have imagined."
At first glance, Chris and Dawn's experience, though heartbreaking, is not unique.
According to charity The Grandparents' Association, 42 per cent of British grandparents lose contact with their grandchildren after a son or daughter's relationship breaks down and, of these, one million are denied contact by one parent.
More often than not, the mother gets custody and in an increasingly global world, with careers forged across continents, there is the very real possibility that the mother will move abroad, taking the children with her - against the wishes of the father and his parents.
Since a 2001 ruling, when a judge allowed a divorced mother to move from England to New Zealand with her child, the tide of so-called "virtual grandparents" has swelled. Their only contact with their grandchildren is online via email, Facebook or video calls on Skype.
Earlier this year, the Mail highlighted the agony of being a long-distance grandparent and shared readers' devastating stories. But what makes the Clarks' situation particularly tragic is that Chris spent more than £30,000 ($63,495) from his retirement fund on lawyers' fees in a desperate bid to keep his beloved granddaughters in the UK.
But as a grandparent, he was excluded from the legal process: he was kept out of court and limited to making a brief statement about what Cecilia and Charlotte meant to him.
But still he tried. Now, he is determined other grandparents shouldn't suffer the same anguish.
On a bright spring morning, the Clarks' spacious home, on a private road in a pretty village, is peaceful. "Too peaceful," sighs Dawn, staring wistfully out of the window.
The living room walls are adorned with photos of their granddaughters. There's Cecilia barefoot amid a patch of bluebells and Charlotte happily shovelling sand into a pink bucket.
Their father, Delwyn, 40, is asleep upstairs, having just returned from his first visit to see his daughters in Australia. Since his relationship with the girls' mother broke down, he's back living in the family home.
"Delwyn first went to Sydney when he was 21," says Dawn. "He did a business course at Chelmsford College then went out with a friend. It had always been a dream of his.
"They got a job selling mobile phone contracts, then realised they could do it themselves, so set up a business and started doing really well."
In 1998, that company wound up and he started another: hiring luxury boats for trips around Sydney Harbour. It was while doing this that he met Camila, now 38, a Brazilian beauty.
"She's a very attractive girl," says Dawn. "So glamorous she could have been a model, and very stylish, too. She had worked in retail, but what she really wanted to do was fashion."
Delwyn met Camila on a night out and the pair began a relationship. A year or so later, in 2005, he phoned his parents to ask them to meet him and Camila on holiday in Barcelona.
"We had a lovely time together, and over the years we met them and other members of her family in Helsinki, Thailand and eventually back in Sydney," says Chris. "It's an awfully long way to Australia, so we often tried to meet halfway."
In 2008, Delwyn called them to say that Camila was pregnant, and in December Cecilia was born.
"We couldn't have been more delighted," says Chris. "We already had one granddaughter, Jada, our daughter Caroline's eldest, and we were overjoyed for Delwyn and so proud."
As far as they knew, their son's relationship with Camila was fine at this stage. "It was quite volatile from the start, but we put that down to Camila's fiery personality," says Chris.
Cecilia grew into a happy, bubbly toddler, and by the end of 2011 Camila was pregnant again.
The subject of them moving to live in Britain came up on a family holiday to Thailand early in 2012. In May, the young family arrived in England and moved into Dawn and Chris's home.
"They were very welcome here," says Chris. "They had their own room with a bathroom; even a car.
"In August, Charlotte was born upstairs, in a birthing pool, and that was a special experience. Camila's mother and two sisters came to stay for four weeks shortly afterwards, and we looked after them and did our best to make everyone feel comfortable."
But Delwyn and Camila had started arguing, and in 2013 she announced she wanted to take her daughters and move out.
Chris helped her find a flat in Wanstead, North-East London. He paid her first month's rent of £1,200 ($2539) and contributed towards furniture and shopping.
Neither Delwyn nor Camila were working, so they were reliant on Chris's support. "I wanted to make sure my granddaughters were looked after," he insists. "It was the least that I could do."
Delwyn and Camila's relationship deteriorated further. On a number of occasions she called the police when he came to pick up his children or sent officers to Chris and Dawn's house alleging that he had kept the girls too long.
Despite all of this, Chris and Dawn were relishing getting to know their grandchildren, and their relationship strengthened by the day.
"They loved it here - they never wanted to go home," says Chris.
Later that year, Camila decided she wanted to return to Sydney. When she realised Delwyn was against the idea, she hired a solicitor to fight her case.
"Delwyn was reluctant to go down that path, but he would do anything not to lose his girls," says Dawn.
"She made all sorts of allegations against him, and in the end we had to hire a barrister. That's when the money started being spent."
A date was set for a "leave to remove" case, meaning that Camila had applied to take the children out of British jurisdiction to Australia, and was providing evidence to support her right to do so, including the claim that she had been offered a job in a jeweller's in Sydney and that her mother, Maria, would move out too to help with childcare.
Meanwhile, Delwyn had to show that it was in his children's best interests for Camila to remain in the UK.
Mr and Mrs Clark's son Delwyn plays with his daughter Charlotte. Delwyn met his daughter's mother Camila on a night out and the pair began a relationship
The law in this area is governed by the Children's Act 1989, under which parents and children have a right to be heard - but, controversially, grandparents have none.
"We were utterly shocked that we didn't get a say," admits Chris. "We weren't allowed in the courtroom, so couldn't hear what Camila or her mother said. Even our barrister would talk to Delwyn and not us."
Chris and Dawn gave statements explaining the impact their grandchildren's loss would have on them. Chris was called to give oral evidence in the Central Family Court in London in September 2014.
He said his piece, then left court - and it was only thanks to the kindness of the judge that the couple were allowed in the courtroom to hear her decision.
"That came as a horrific blow," says Chris. "Just terrible. We were deflated. It wasn't the money we'd spent or the injustice of what had been said: all we were thinking of was those two little girls.
"We were not trying to get custody of them. If it had gone our way, we wouldn't have walked away from Camila. We would have supported her to bring them up. But we weren't prepared for it to go so wrong."
They had just ten days after the hearing before Camila, Cecilia and Charlotte flew to Sydney.
"It was a very stressful time," says Dawn. 'The judge said we had to spend as much time with them as possible. One day I remember was particularly heartbreaking.
Delwyn with elder daughter Cecilia. Part of the court judgment included an order compelling Camila to Skype Delwyn once a week, and to return to Britain with her daughters once a year at her own expense
"We took the kids to Colchester Zoo. There was a train, which you rode around on to look at the animals, and at one stop Delwyn thought it would be funny not to get back on. Little Cecilia went crazy, screaming: 'Daddy! My daddy! Stop the train! I won't go without my daddy!' She just adores him."
They didn't go to the airport to say goodbye. Neither did Delwyn. They worried it would be too emotional - for him and the girls. "They'd been told it was a holiday," says Dawn. "Three days before they left, we dropped them off with their mum. They got out of the car, waved goodbye and that was it."
Part of the court judgment included an order compelling Camila to Skype Delwyn once a week, and to return to Britain with her daughters once a year at her own expense. Again, no provision was made for the grandparents.
"We've had three Skype calls and the first two were very frustrating," says Dawn. "The TV was on in the background and we couldn't get Cecilia's attention.
Legally, there is little Chris and Dawn can do to improve their situation. Change in this area has been on the cards for a while, but nothing has yet been done to make things better for grandparents.
In 2011, a government report recommended enshrining contact rights in law. Four years later, however, nothing has changed.
For now, Chris and Dawn are doing what they can to maintain a long-distance relationship. The girls are too young to use email, though this will become a valuable line of communication in the future.
Chris and Dawn may yet save up for a trip to Australia or a holiday with the grandchildren halfway if Camila agrees to it.
"I can't bear to think that we might not see them again," says Chris. "When they are older, I have no doubt they'll come back to be closer to their dad. And when they do, I shall tell them that we did everything possible to stop them going.
"We didn't give up. We fought. Right to the very last day."
- Mail Online