National's share of the party vote in the city had been increasing since 2005 but leapt by from about 44 per cent in 2008 to almost 52 per cent last weekend.
"There was a trend there but a 7-point jump is quite considerable and I think given that the earthquakes have dominated people's lives down there for the last 15 months, you'd have to say the way in the which the Government has responded, to a certain extent has been put to the test with the general election.
"We've had the prime minister in the city weekly if not more since the September event and we've had a lot of Government ministers there. We have as a Cabinet taken a huge focus on doing what we can to recover. What we can't do is make it call go faster but I think this is a bit of an endorsement that the Government has approached the problems in Christchurch from a totally appropriate and empathetic point of view."
Many people in Christchurch continued to live in "less than optimal conditions".
"When people are in that mode I think they want an optimistic message I don't think they want the daily dose of pessimism and negativity that has been fed to them by a number of Labour MPs."
However Mr Burns said last weekend's results reflected "a tale of two cities".
"In parts of Christchurch, to the north and the west there was not a lot of damage, everyone's got some and in those areas the Government's consistent messaging that they're doing a good job on the quakes has probably been accepted. On the eastern side of the city, the damaged areas, the message hasn't gone so successfully."
Labour's Christchurch East MP Lianne Dalziel who has been one of the visible advocates for quake hit residents in the city increased her share of the candidate vote even though her majority fell.
Mr Burns put National's success down to "brand Key".
"The Prime Minister has been through Christchurch 50 times in the last year and the National MPs have pretty shamelessly stuck like glue to him. When a very popular prime minister's telling you all is well that's a message that a lot of people are going to accept."
Mr Burns made no apologies for Labour's attacks on the government's handling of the quake response which had been marred by Mr Brownlee's broken promise that affected homeowners would not lose the equity they had in their homes and also by poor communications.
"If that means I'm seen by some who haven't done too badly in the quakes as being less than positive well that is the role of an effective electorate MP.
"Offsetting that has been the enormous help that we as MPs have provided to our people hundreds and hundreds of people helped with constituency issues with EQC and insurance, and the dozens of meetings organised for constituents.
"I'm sitting on a knife edge here, but I think the specials will carry me through because of that work."