Boris Johnson's government will announce a new budget on 6 November, Sajid Javid has said.

The chancellor suggested his first budget would take place after Brexit, despite parliament passing a rebel bill that compels ministers to request an extension of article 50 by 31 October.

In the event of a no-deal Brexit, a Treasury source said Mr Javid would be likely to rip up the plans and deliver an emergency statement, with a Budget to follow within a few weeks.

The surprise announcement for a full financial statement came at the start of a make-or-break week, as the prime minister scrambles to seek agreement with Brussels ahead of a crucial summit on Thursday and Friday.

“This will be the first Budget after leaving the EU," Mr Javid said.

"I will be setting out our plan to shape the economy for the future and triggering the start of our infrastructure revolution. This is the right and responsible thing to do – we must get on with governing.”

It is understood that the upcoming Budget could focus on infrastructure - an area where Mr Javid has focused his firepower since entering No 11 in July.

Nicola Sturgeon, the Scottish first minister, said it was clear the government was "making it up as they go along" - and there was no guarantee Mr Johnson would still be in power.

She told BBC Radio 4's Today programme: "I have to say, I think it's another example of this government making things up as they go along.

"I'm not sure they will still be in office on 6 November and it doesn't appear to be at all certain that we will leave the EU on 31 October."

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The SNP leader said there was "a lot of water to flow under the bridge" before 6 November.

Labour's Jon Trickett questioned how the government could pass a Budget without a parliamentary majority, after the prime minister stripped the whip from more than 20 Tory MPs.

"We do need a budget but we need a budget which signals a change of direction for our country," he said.

"All the cuts which have done so much damage to our communities and the money handed over to the wealthiest in our society, we need to change your direction so there should be a budget but I doubt if we're going to get that one from the Conservatives.

"In fact I'm going to be surprised if there is a budget at that time because they have no idea whether they're going to get this Brexit proposal through the House or not."