The director and chairman of the John Smith Institute, the think tank set up in memory of the late Labour leader which has close links with Gordon Brown, have resigned.

The director and chairman of the John Smith Institute, the think tank set up in memory of the late Labour leader which has close links with Gordon Brown, have resigned.

But Wilf Stevenson, outgoing director, denied their departures were a result of criticism from a Charity Commission investigation that last month accused the organisation of "inappropriate" party political activity.

Mr Stevenson, a lifelong friend of the Prime Minister, and Lord Haskel, the chairman, were targets of a right wing internet campaign that claimed the institute was primarily a vehicle to promote Mr Brown's political ambitions and that events held at No 11 Downing Street during his chancellorship breached charity rules on political neutrality.

Last month, the Charity Commission ruled there was "no evidence" to support an allegation that Mr Brown, chancellor during the period in question, used the institute to "further his political aspirations".

However, shadow cabinet member Chris Grayling said the resignations in the wake of the commission's report "suggest something was seriously amiss". He urged the Electoral Commission to take up its own inquiry into the running of the institute.

Far from running from the Charity Commission conclusions, Mr Stevenson said that he had been seeking to resign since 2006 but had stayed on to deal with the inquiry. Other changes were also on hold.

"We had a brilliant report from the commission which concluded there had been absolutely nothing in any of the allegations made against us, as a result of which I can now stand down," he said. Lord Haskel remains an ordinary trustee.

The commission's report on July 18 concluded that the institute was producing work which fell within its charitable purpose, but added: "The trustees had allowed the institute to become exposed to concerns that it supported government policy and was involved in party political activity inappropriate for a charity. The trustees did not adequately manage the risks to the independence and reputation of the institute."