SIR Gus O'Donnell, the head of the Civil Service, has been called upon to give assurances that the creation of a new highly paid official at Holyrood will not be allowed to become an "independence tsar" for the SNP Government.

Concerns have been raised by Lord Forsyth, the former Conservative Scottish Secretary, that the Civil Service in Scotland is becoming politicised and used to promote separation from the rest of the UK.

He and other politicians, including the three leaders of the opposition parties at Holyrood, recently aired their fears that Sir Peter Housden, the top civil servant in Scotland, had “gone native” and was actively promoting independence.

However, last week, Sir Gus responded by backing his colleague, telling critics: “It is right that civil servants working to their respective administrations undertake the relevant work to support their ministers to pursue their aims, whether or not these are the subject of controversy.”

Now concerns are to be raised in the House of Lords about the appointment by First Minister Alex Salmond of a director general for strategy and external affairs on a salary between £101,500 and £208,100.

Lord Forsyth said: “How they can find £208,000 a year, plus all the implications for a final salary scheme beggars belief.”

The Scottish Government said the new post will “strengthen our capability to deliver the Government’s programme for Scotland”.