David Maclean has announced his resignation as Tory chief whip following the removal of Iain Duncan Smith.

Maclean said that his resignation was necessary to ensure that the Whips' Office was seen to be neutral during the forthcoming leadership contest.

Stepping down from his behind-the-scenes role, Maclean said that recent events had given him "a higher public profile than is customary" for someone in his position.

Maclean's letter to the party's MPs said his resignation was "the honourable thing" to do.

"Now that we have a leadership election it is vital that the whole Whips' Office is, and is seen to be, neutral and impartial," he wrote.

"I cannot let my past commitment to the leader give rise to any suggestion that the office will not operate with the highest standards of neutrality and my departure will make that abundantly clear.

"It will also give the new leader a completely free hand to appoint a new chief whip."

In the meantime, Maclean's current deputy, Patrick McLoughlin, will take over as acting chief whip.

Maclean closed his letter with a plea for party unity following the recent turmoil.

"I urge colleagues over the next few weeks never to forget that as Conservatives we agree on much much more than we disagree," his letter read.

"If we all behave with restraint and dignity we can come out of this process stronger and able to challenge this failing government even more robustly.

"The country rightly looks to us to ensure that the business of opposition is vigorously maintained.

"We have important legislation returning from the Lords in the next two weeks, followed by the Queen's Speech and we must show the media and the country that we are an effective opposition, capable of being a competent government."