Ministers have “absolutely got to get a grip” on Brexit and reveal the impact of a “no deal” scenario, Emily Thornberry has said.

The shadow foreign secretary mocked Theresa May and her Cabinet, claiming the Prime Minister is “bereft of ideas” and “putting suggestion boxes around Parliament” while Foreign Secretary Boris Johnson is “making it up as he’s going along”.

Ms Thornberry also likened Anne Marie Morris to former BNP leader Nick Griffin after the MP was suspended from the Tory parliamentary party for describing the prospect of leaving the EU with no deal as “the real n***** in the woodpile”.

Emily Thornberry deputises for <a href=Labour leader Jeremy Corbyn at PMQs (PA)">Emily Thornberry deputises for Labour leader Jeremy Corbyn at PMQs (PA)

Ms Thornberry deputised for Labour leader Jeremy Corbyn at Prime Minister’s Questions as Mrs May was absent due to her involvement in the King of Spain’s state visit.

This resulted in First Secretary of State Damian Green answering for the Government and claiming Labour has had “nine different plans” on Europe, which has led to splits among the Opposition.

Exchanges during PMQs were noticeably punchier between the two stand-ins, with Ms Thornberry seeking to make fun of Cabinet ministers and their leadership ambitions.

Ms Thornberry said she believed there were “plenty of other people on the front bench who would love the opportunity to audition as prime minister” if Mr Green did not want to continue in the role.

First Secretary of State Damian Green (PA)First Secretary of State Damian Green (PA)

She added that the Government was in a “mess” after threatening to walk away before Brexit talks began.

“Isn’t the truth now that we’ve got a no deal option on the table but they won’t tell us what that means?” she said. “They’ve got contingency plans but won’t let the public see them.

“We’ve got a Chancellor demanding transitional arrangements, which a no deal option makes impossible. We’ve got a Foreign Secretary making it up as he’s going along.

“We’ve got a Brexit Secretary so used to overruling his colleagues that he’s started overruling himself. And we’ve got a Prime Minister so bereft of ideas that she’s started putting suggestion boxes around Parliament.

Brexit Secretary David Davis (PA)Brexit Secretary David Davis (PA)

“But as a country we have got 20 months to go until Brexit. We have absolutely got to get a grip.

“If the party opposite hasn’t got the strength for the task, we’ve absolutely got to get rid of them.”

Mr Green said negotiations are “going well”, with the Government wanting to protect the rights of EU citizens living in the UK and Britons living in the member states as soon as possible.

He said: “That is the sign of a practical, pragmatic Government getting on with work in the interests of the British people.

“What we would have, as we’ve seen, from the Labour Party is they’ve so far – I’ve counted – had nine different plans on Europe.

“They want to be both in and out of the single market, in and out of the customs union.

“They said they wanted to remain, they voted for Article 50 – they split their party on that.”