The Conservative Party has been hit by the resignation of Barry Legg, its chief executive.

Following the announcement former frontbencher Crispin Blunt renewed his calls for Iain Duncan Smith to step down as party leader.

The resignation, revealed on Wednesday evening, followed a decision by the party board to abolish the post of chief executive and "devolve responsibilities to other members of the management team".

The move will be seen as a blow to the party leader, who had appeared determined to keep Legg in his post.

In a statement, Duncan Smith said he was "sorry" that the reorganisation had led to Legg's departure.

"I would like to thank Barry for his work over the past three months and am sorry that the reorganisation means that he will now be leaving. I would like to thank Barry for his work, both as my chief of staff and as CEO," he said.

Legg also expressed his regret at the move.

"I am sorry to be leaving so soon, and do so regretting that I have not been able to do more. I wish the party every success for the future."

In a snub to Duncan Smith, members of the party board decided to dispense with the post of chief executive officer after a "strategic review of the organisation and operation of Conservative Central Office".

Conservative MP Derek Conway, who had been critical of Legg's appointment, said that Duncan Smith "was right to resolve the matter".

"He has shown leadership in doing that. It will have been a difficult decision to take because he was a friend. But leadership is about taking difficult decisions," said Conway.

"So the matter, as far as I am concerned, is now closed and we should concentrate on supporting Iain Duncan Smith's leadership."

Former energy spokesman Crispin Blunt accepted that Legg had put the interests of the party first by resigning.

But Blunt, who resigned last Thursday, renewed his calls for a new party leader.

"This is the appropriate moment to consider this issue because if we don't do it now then we will not be giving a new leader sufficient time to lead the party before the next general election," he told the BBC.

"It is simply my view that it is more difficult for Iain to be able to convince the electorate of his claim to be prime minister than other Conservative candidates who may be able to succeed him."

Legg had come under increasing pressure to quit after just eight weeks in the job.

The former MP was appointed by Duncan Smith after he sacked reformer Mark MacGregor.

But members of the party's board were angered by the failure to consult them before making the decision to appoint Legg.

Several had threatened to quit over the affair.

Legg's past as a member of Westminster Council during the homes-for-votes scandal and his links as a company director for a firm found to have broken pension laws added to his difficulties.

During his time as an MP he was also a key rebel opposing the Maastricht Treaty.