THERESA May has been accused of “treating Scotland with contempt” after it has emerged that Scottish secretary David Mundell will only have a part-time place on the special cabinet committee planning the UK Government’s strategy on Brexit.

The Liberal Democrats accused the Prime Minister of being “dead-set on a hard Brexit” because half of the 12 cabinet committee places have gone to ministers who voted to leave the European Union.

No 10 declined to comment, saying the membership of the EU exit and trade committee would be announced next week but leaked details show that it will be split between six ministers, who backed Leave, and six, who backed Remain.

However, controversially, the territorial secretaries of state will only attend “as required” to do so by Mrs May.

Angus Robertson, the SNP’s new deputy leader, who leads the party at Westminster, said: "The revelation that the Scottish Secretary is not a full member of Theresa May's Brexit cabinet committee is deeply embarrassing for David Mundell but more importantly it also seriously undermines Theresa May's claim that Scotland will be fully involved in the Brexit negotiations.”

He went on: “The UK Government is treating Scotland with contempt. But make no mistake, the SNP will ensure that Scotland's voice is heard loudly and clearly in the Brexit process.”

He added: "The people of Scotland voted overwhelmingly to remain in Europe yet we face being dragged to the EU exit door by a Tory government with just one MP out of 59 in the country and as the ugly reality of the Tory vision of Brexit Britain becomes clear, we will explore all options to protect Scotland's place in and relationship with EU."

Tim Farron for the Lib Dems said the “line-up of hard Brexiteers is a further sign that the Government wants to pull us out in the most aggressive way possible, abandoning the single market and crippling the economy.This is a case of May letting the foxes into the hen-house”.

The party leader added: “She is dead set on a ‘hard Brexit,’ putting jobs at risk and happy for costs to rise from our shelves to our petrol pumps. The Liberal Democrats are the only real opposition to this Conservative Brexit Government.”

The Brexit cabinet committee has already met at least three times but the details of its discussions and membership have been thus far kept secret.

Among those on the Brexit committee are the so-called “three Brexiteers,” Boris Johnson, the foreign secretary, Liam Fox, the international trade secretary, and David Davis, the Brexit secretary. Also on are fellow Leavers Chris Grayling, the transport secretary, and Priti Patel, the international development secretary.

On the remain side, the membership also includes Mrs May herself as chairwoman, Philip Hammond, the chancellor, Patrick McLoughlin, the party chairman, Amber Rudd, the home secretary, and Damian Green, the work and pensions secretary.

Cabinet committees are sub-committees of the full cabinet and focus on specific policy areas. Consequently, their membership is much smaller.