Bridges' former leadership rival Judith Collins in up one point to 6 per cent.
Deputy Prime Minister and New Zealand First leader Winston Peters is steady on 4 per cent.
The last poll was taken in the midst of the Jami-Lee Ross crisis in which the MP was accused of being the leaker of Bridges' travel expenses.
Ross said he had suffered a breakdown after being criticised by Bridges and deputy leader Paula Bennett for the way he treated women and had taken leave.
But he returned to Parliament after being named as the likely leaker and accused Bridges of being corrupt and he quit National at the same time the caucus was expelling him.
In the fallout from that, National dropped below Labour for the first time in Government in the 1 News Colmar Brunton poll and now it is back in front.
Translated to seats in the House, New Zealand First would be out of Parliament altogether - perhaps a motive for the parties of Government to revisit lowering the threshold to four per cent instead of five per cent.
Labour with 54 seats and the Greens with 7 seats would be able to form a majority Government with National's 58 seats and Act's 1 - assuming Act leader David Seymour held Epsom.
The Maori Party, which was tossed out of Parliament last year, also stayed steady on 1 per cent.
In the time since the last poll was taken, the Government has been under pressure over petrol prices, and the decision to grant residency to convicted drug smuggler and Czech national Karel Sroubek, although that decision was reversed last week.
Ardern told 1 News she was very happy Labour was finishing the year stronger than it had started.
"We still make up a majority as a coalition Government."
Bridges was pleased with the poll.
"It shows that National has come through a tough period and it is very focused on what Kiwis are worried about heading into Christmas - the bread and butter issues of the cost of living, tax and law and order," he told the Herald.
On the issue of Judith Collins rising up the preferred Prime Minister stakes he said: "I don't think this is a beauty contest. It is the party vote ultimately that matters and under my leadership, National is proving strong and resilient."
But he said 2019 would be a massive year and he was far from complacent.
Judith Collins, when asked if she would consider being the leader, said it was not something that had come up at all.
"My view is that I support the leader, I support the caucus and the party," she told 1 News.
On the question about economic outlook, 37 per cent thought the economy would be in a better state over the next year (up four), and 34 per cent thought it would be in a worse state (down seven).
