The tax authority recently announced a raft of internal appointments through internal memos, copies of which have been seen by Accountancy Age.

Among the moves are the appointment of Melanie Dawes to take over the key role of the Large Business Service when David Garlick retires at the end of this year.

A source familiar with the issue said: ‘It’s a fairly technical role. It has caught a lot of people in HMRC by surprise, the suggestion being that the Treasury want to play it a bit more sensitively to business.’

The Large Business Service is the major point of contact between big business and the taxman, and Garlick has been responsible in recent months for putting together risk profile scores of all major businesses to focus HMRC resources.

The department is also looking at ‘increasing joint working between HMRC and the Department of Work and Pensions,’ the memo says.

Experts suggested the move might be related to A-Day implementations, though the departments also share an interest in social security payments, given HMRC’s role in tax credits.

Insiders suggested the moves were to be announced a month ago, but were pulled when Sir David Varney’s move to the Treasury was announced amid uncertainty as to whether they would go ahead.

Geoff Lloyd will become director of corporation tax and VAT, while Doug Tweddle will head a Frontiers and International Directorate.

HMRC sources confirmed the moves were due to take place.