Downing Street has ruled out an early general election, as Theresa May stretched her lead over Labour to a post-2015 high in the latest poll.

The ICM survey for The Guardian put the Conservatives on 45% (up one point from a similar two weeks ago), ahead of Labour on 26% (down two), Ukip on 10% (down one) and LIberal Democrats on 9% (up one).

Even though the poll was taken after Philip Hammond's U-turn on his Budget increase in National Insurance for the self-employed, the Prime Minister and Chancellor were rated the best team to manage the economy on 44% (up one) compared with their Labour opposite numbers Jeremy Corbyn and John McDonnell on 11% (down one).

The new poll will add to pressure on Mrs May from Conservative MPs who believe she should take advantage of her commanding position to seek to extend her majority in the House of Commons.

It is widely believed the Prime Minister would be able to secure the two-thirds majority among MPs needed to overturn the provisions of the Fixed-Term Parliaments Act which require a five-year period between elections.

But Mrs May's official spokesman told a Westminster media briefing: "There is no change in our position on an early general election, that there isn't going to be one... It is not going to happen.

"There is a Fixed-Term Parliaments Act.

"We have been clear that there isn't going to be an early general election and the Prime Minister is getting on with delivering the will of the British people."

With polls regularly giving Conservatives a double-digit lead over Labour, some Tory MPs have argued an early election would give Mrs May an opportunity to secure a comfortable majority in the House of Commons.

They warn that her precarious 17-seat working majority will leave her vulnerable to rebellions during the protracted process of negotiating withdrawal from the EU.

ICM director Martin Boon said the current 19-point lead had only been topped by the Conservatives on three occasions in the 34-year history of its polls for The Guardian - twice in 1983 when Labour was led by left-winger Michael Foot and once in 2008, when Gordon Brown was reeling from the impact of the financial crisis.

And Mr Boon said Tories were in the lead in almost all sectors of the economy.

"It's so desperate for Labour that it's also nearly a 'full house' across standard demographics," he said.

"Only members of non-white communities offer up a Labour lead over the Tories, with (social class) DEs tied. When 18-24s split 41% versus 29% for the Conservatives, Labour can only be in some sort of historic mess."

A fresh election would allow the PM to claim her own personal mandate from the electorate.

But it would risk triggering an effective re-run of the 2016 EU referendum, with Liberal Democrats and Ukip seeking to turn it into a battle over the nature of Brexit.

While Tory strategists are confident of defeating Labour in an early election, some are thought to believe that this may be counter-productive in the longer term as it might hasten the departure as leader of Jeremy Corbyn, who polls suggest is unpopular with many voters.

The poll found that Ukip is regarded as the least honest of the major parties by voters, with 8% rating them honest against 38% dishonest.

Conservatives were the least distrusted (19% honest, 26% dishonest), against Labour (13% honest, 24% dishonest) and Liberal Democrats (honest 11%, dishonest 25%).

:: ICM Unlimited interviewed 2,012 adults between March 17 and 19.