Downing Street has launched an outspoken attack on Labour and the Liberal Democrats accusing the two parties of not “backing the UK team” as the country enters Brexit talks.

Theresa May’s official spokesperson said the two parties are trying to “frustrate the will of the British people”, after they said they would take measures to ensure any deal Ms May secures is right.

The Prime Minister’s spokesperson said: “While others are seeming to make clear that they want to frustrate the will of the British people by slowing down the process of leaving and trying to tie the Government’s hand in the negotiation, the Government is getting on respecting what the British people have decided and making a success of Brexit.”

The spokesperson added: “If you are backing the UK team, you want them to be able to go into the negotiation and get the best deal possible.”

Speaking on Saturday, Labour leader Jeremy Corbyn said that when the triggering of Article 50 is debated in the Commons his party would put forward an amendment to it, that seeks to secure the right kind of market access and protections for workers.

He added: “We are respecting the result of the referendum. It might not be the one we wanted but it's the one we’ve got.”

When the Lib Dems won a by-election in Richmond Park, overturning a large Conservative majority after fighting an anti-Brexit campaign, the party’s new MP Sarah Olney said she would vote against the triggering of Article 50, while leader Tim Farron called for a new referendum to be held on the terms of the deal Ms May secures.