Britain’s top civil servant has been called upon to investigate the use of impartial officials by a group of Conservative MPs preparing a new Brexit plan for Theresa May.

Cabinet Secretary Mark Sedwill has been asked to establish whether provision of civil servants to the Alternative Arrangements Working Group breaches Whitehall rules.

The Group - made up entirely of Conservative MPs, predominantly backbenchers - has been meeting in the Cabinet Office this week with around a dozen civil servants from the Department for Exiting the European Union, the HMRC and the Northern Ireland Office.

Lib Dem leader Sir Vince Cable has signed a letter to Mr Sedwill which reads: "I am writing following reports that civil servants may have been advising Jacob Rees-Mogg and Nicky Morgan on their alternative Brexit proposals. These plans were apparently hammered out in the office of housing minister Kit Malthouse.

'Much-valued independence and impartiality'

The letter sent to Mark Sedwill

"Please can you confirm whether it is correct that civil servants have been providing this support and whether any other civil service resources have been used?

"If they have, I would question whether using civil servants to support a backbench initiative is either a sensible use of taxpayers’ money or maintains the much-valued independence and impartiality of civil servants."

It continues: "Section 7.1 makes it clear civil servants are there to support government (and presumably not backbenchers or opposition parties)

"Also section 7.2 which underlines the importance of Ministers maintaining the political impartiality of the Civil Service

"And finally, section 7.3 which underlines the importance of not using public funds for party political purposes (securing an alternative deal, palatable to Conservative backbenchers would clearly fall into the category of a party political purpose)."

The letter also calls on Mr Sedwill to reveal the precise extent of civil service time spent on the meetings which are considering the so-called Malthouse Compromise.

It asks whether any civil servants have complained under the code.

'Quest to find a unicorn'

Lib Dem Brexit spokesperson Tom Brake. Image: Keith Edkins

The government's instruction to civil servants to support the group has been taken as an indication of support for the plan by No 10.

Liberal Democrat Brexit spokesperson Tom Brake said:“If Ministers have been instructing civil servants to assist Jacob Rees-Mogg and Nicky Morgan in their quest to find a unicorn, that can piece the Tory party back together again, this would be a flagrant breach of Ministerial rules.

"Any costs associated with such a naked party political stunt would have to be reimbursed to taxpayers and instructions issued to all Ministers to refrain from abusing civil service resources in this way."

A Government source told talkRADIO: “Civil servants have been assisting Ministers — and it is clearly an appropriate use of resources to help deliver Brexit legislation through Parliament.

"Liberal Democrats should declare their interest as a party that wants to ignore the will of the British people.”

Letter in full

Mark Sedwill,

I am writing following reports that civil servants may have been advising Jacob Rees-Mogg and Nicky Morgan on their alternative Brexit proposals. These plans were apparently hammered out in the office of housing minister Kit Malthouse.

Please can you confirm whether it is correct that civil servants have been providing this support and whether any other civil service resources have been used?

If they have, I would question whether using civil servants to support a backbench initiative is either a sensible use of taxpayers’ money or maintains the much-valued independence and impartiality of civil servants.

I believe there are a number of sections in the Cabinet Manual which are relevant if my understanding is correct.

Notably, section 7.1 which makes it clear civil servants are there to support government (and presumably not backbenchers or opposition parties)

7.1 Civil servants are servants of the Crown. The Civil Service supports the government of the day in developing and implementing its policies, and in delivering public services.2 Civil servants are accountable to ministers, who in turn are accountable to Parliament.3

Also section 7.2 which underlines the importance of Ministers maintaining the political impartiality of the Civil Service

7.2 Ministers are required to uphold the political impartiality of the Civil Service and not ask civil servants to act in any way that would conflict with the Civil Service Code or the requirements of the Constitutional Reform and Governance Act 2010.4 Ministers also have a duty to give fair consideration and due weight to informed and impartial advice from civil servants, as well as to other considerations and advice in reaching policy decisions.5

And finally, section 7.3 which underlines the importance of not using public funds for party political purposes (securing an alternative deal, palatable to Conservative backbenchers would clearly fall into the category of a party political purpose)

7.3 In addition, civil servants should not be asked to engage in activities likely to call into question their political impartiality or give rise to the criticism that resources paid from public funds are being used for party political purposes.6

If civil servants have been used in this way, please could you confirm how much civil service time has been spent and at what cost on supporting Jacob Rees Mogg and Nicky Morgan, whether any on-going support is going to be provided and whether any civil servants have complained under section 7.6 of the Code.

I look forward to your prompt response on these points.

Thank you for your assistance.