Mr Dutton holds his nearby outer-Brisbane seat of Dickson by the narrow margin of 1.6 per cent and campaigned heavily with Mr Ruthenberg during the Longman byelection. It is one of seven Coalition-held seats with margins of less than 4 per cent after the 2016 federal election. Griffith University election analyst Paul Williams said those seats were now vulnerable. “They are, especially the ones outside Brisbane, so obviously seats like Bonner and Brisbane would be less vulnerable because of (Prime Minister Malcolm) Turnbull’s appeal," he said. “But once you get outside the capital city, in the outer suburbs, where Malcolm Turnbull becomes less popular, the swings will be greater.

“So Ross Vasta in Bonner may be taking a bit more comfort than Peter Dutton in Dickson. “Peter Dutton has a real problem on his hands.” Dr Williams agreed the conventional wisdom was that byelection results are not good indicators for results at a full federal election. “But it is very difficult comparing a byelection in one state with a byelection in another,” he said. “So the story in Braddon is very different to the story in Longman.”

Professor Clive Bean, professor in politics and voting trends at Queensland University of Technology, agreed Mr Dutton could lose his seat, but said it was part of a long voting trend against the government. "He may very well, but I don't think the byelection is a very good pointer towards that," Professor Bean said. "Byelections nearly always go against the government and in this seat there was a local candidate issue with the service medal and I suspect that counted against the government." Professor Bean said voters in all five byelections - originally triggered by the 2017-18 citizenship crisis - may well have felt that it was a"technical hitch" and MPs had done nothing wrong and were simply returned. "I think there was fair bit of thought that it was the constitution itself that was 'at fault', or outdated, and I think that has been lost from the debate, but not necessarily from voters' minds," he said.

Professor Bean said long-term voting trends clearly showed the government was vulnerable in Queensland's marginal seats and that the outcome of the byelection itself did not necessarily relate to this. "What it probably does do is reinforce a notion that Labor is ahead of the Coalition ... and there are seats that may fall to Labor as a result of the general political trend," he said. Loading "But to say the byelection result is a pointer to any of that is probably a little bit optimistic." There were five byelections held on “Super Saturday”; one in Queensland (Longman), two in West Australia (Perth and Fremantle), one in South Australia (Mayo) and one in Tasmania (Braddon).

Dr Williams said One Nation’s strong vote in the regions on the edges of big cities continued in Longman. One Nation’s Longman candidate Michael Stephen received 15.9 per cent of primary votes. “They will be buoyed by that 16 per cent,” Dr Williams said. “Getting a (6.5 per cent) swing to them in a Melbourne Cup field. They will not be unhappy with that result." The Greens received 4.8 per cent of the byelection vote, similar to their result at the 2016 federal election.

Prime Minister Malcolm Turnbull on Sunday. Credit:Brook Mitchell Mr Turnbull said the result in Longman was an “average-sized swing” against the government at a byelection. “There is nothing remarkable about it at all," he said. Mr Turnbull said the LNP would "look very seriously and thoughtfully and humbly at the way in which the voters have responded". The seven Queensland Coalition seats under the microscope are:

Dawson – Central Queensland seat north of Mackay, held by George Christensen with a margin of 3.3 per cent. Bonner – Brisbane bayside-based seat held by Ross Vasta with a margin of 3.4 per cent. Dickson – north Brisbane seat held by Mr Dutton with a margin of 1.6 per cent. Petrie – Redcliffe-based seat, held by Luke Howarth, with a margin of 1.6 per cent. Flynn – a Gladstone-based seat held by Ken O’Dowd with a margin of 1 per cent.