"I watched him grow in those six months, and it's a real shame he did not get to be the long-term prime minister, but that's politics.
"Everyone likes and respects him - he's hard working, he thinks things through and stands by his principles but he's not overbearing with them - it's a loss, as an individual I had the utmost respect for him and still do and wish him and his family all the best."
He did not think the upcoming deliberations on who would be the next leader would be destabilising.
"It depends how it all happens ... but the retreat we had last week was one of the best I have been at in terms of everybody being galvanised and focused on what we have to do win the 2020 election."
He said he was confident there would be a good process to select the next leader from the talent and ability within the caucus, and that National would be well served by its new leader, whoever that might be.
Mr Scott said Mr English had had an amazing political career, representing people in Southland and the country, and as Prime Minister, getting up from losing an election to carry on and essentially bringing in more votes than any other party in the last election.
"I'm a little bit surprised he decided to leave now, but he's leaving the caucus in good shape, so in a way it was good timing."
Ikaroa-Rawhiti Labour MP Meka Whaitiri said she had mixed feelings when she heard the news.
"It was only this week that he said publicly there would be no change in leadership. This reminds all of us politicians how politics can change in 24 hours."
Having said that, she acknowledged his 27 years of service and the contribution his wife, Mary, and family had also made.
"I have nothing but respect for his long service and the way he has conducted himself."
She said she met Mrs English first, many years ago, when they faced each other on the netball courts in Wellington.
"She played for St Caths and I played for P.I.C, she was the goal keeper and I was the goal shoot.
"She introduced me to Bill on a plane - he was on the seat opposite reading some papers.
"I said 'Hi', and he looked up from his papers and said 'I remember you. Mary, you would always drag me up to Hataitai to play against that team and they'd thrash you', and then he went back to reading his papers again, and she hit him across the arm."
Ms Whaitiri said such relationships were an important part of politics, despite being in opposing parties, and that like many others she wished him and his family all the best.
Napier Labour MP Stuart Nash said Mr English had done a great job as a finance minister and as Prime Minister.
"He has achieved far more than most and I wish him the best of luck - he's been here a long time and it does take a toll on your family.
"While I don't necessarily agree with his politics, there's no doubting his commitment to the people of New Zealand - it's another old war horse departing Parliament."