Sir Keir Starmer has used an emergency Commons debate to appeal to ministers to take a no-deal Brexit “off the table”.

Downing Street announced on Tuesday, after a three-hour cabinet meeting, that the Government would “ramp up” no-deal preparations – with 3,500 troops on stand-by and an extra £2 billion set aside across 25 Whitehall departments.

The shadow Brexit secretary, who was granted emergency Commons time under a parliamentary procedure known as SO24, said Labour MPs would not be forced into accepting Theresa May’s deal in order to prevent a no-deal scenario as he accused the Government of “running down the clock” on Brexit.

He said: “There’s no such thing as a managed no deal, I’ve repeatedly said a no deal is not credible, it’s not viable, it is a political hoax intended only to put pressure on members of this House to back the Prime Minister’s deal.

“Even if the Government did choose to push ahead with a no deal, I’m convinced that Parliament would stand in its way. The overwhelming majority of members in this House would not countenance a no-deal Brexit.”

Sir Keir went on to pay tribute to Tory MPs such as Nick Boles and Anna Soubry, who said they would resign the whip if the Government did pursue a no deal, adding: “I suspect they’re not alone.”

“We have a Prime Minister unable to put her deal to the vote and no prospect of further renegotiation, rather than trying to reach across Parliament to break the deadlock we have a Government that is now actively pursuing a policy that’s not supported by the Cabinet, not supported by Parliament and not supported by the country”, he said.

He added: “It is reckless and irresponsible, it’s an indictment of a wasted year, even now I’d urge the Government to take no deal off the table and find a sensible way forward.”

Labour colleague Lloyd Russell Moyle (Brighton Kemptown), intervening on his speech, suggested the PM should look at extending Article 50 to get more time to secure a better deal and the shadow Brexit secretary replied: “I do agree that serious consideration needs to be given to the timetable now set by Article 50.

“Because by the 14th of January we will just be nine weeks away from the proposed date of leaving the EU, and on any view the government will then have to make a choice what to do next, and no ‘Plan B’ has ever been forthcoming.”

Brexit Minister Chris Heaton-Harris, responding, said no deal “remains a risk” if Parliament does not support the PM’s deal.

He said: “This Government has been clear that we do not expect or want a no-deal scenario, delivering the deal negotiated with the European Union remains our top priority it is also the best way to deliver on the democratic choice of the British people.

“Our effort to get this deal has not changed, however with 100 days until we leave the European Union the Government’s continued duty is to prepare for every eventuality including a no deal scenario.”

Labour’s Stella Creasy (Walthamstow), intervening, asked if Government accepted “any responsibility for how it’s come to this”.

Mr Heaton-Harris replied: “I’d love to have a moment of introspection, I’d love to have been in the negotiating room, but we now have on the table a very good deal for this country and the best way to mitigate against a no deal is to vote for that deal.”

More than 10,000 civil servants are now working on Brexit with a further 5,000 in the pipeline “which will allow us to accelerate our preparation as necessary and hopefully for a deal”, he added.

He said: “The Government has no intention to use troops in our no deal planning at all.”

Labour’s Stephen Kinnock called the PM’s delaying of the vote on the Brexit deal a “constitutional outrage”.

The MP for Aberavon said: “Theresa May’s disastrous handling of the Brexit negotiations is entirely of her own making.”

He said: “She has been talking up the prospect of no deal in order to bounce MPs on both sides of the house into supporting whatever deal she asks us to approve.

“Her gameplan is simple, to scare the living daylights out of us and repeating ad nauseam that the only choice will be between her deal and no deal at all.”

Mr Kinnock added: “It is vital that Parliament rejects her scaremongering and blackmail tactics, because they are built on an empty threat. The fact is that no deal is simply not going to happen.”