Concerns over the behaviour of MPs have yet to be investigated despite being raised up to four years ago, John Bercow has said.

The Commons Speaker called for the Government to urgently establish the Privileges Committee in order to clear the backlog.

Labour also questioned if the delay in setting up the body was due to Prime Minister David Cameron knowing one of his ministers has breached parliamentary rules.

Conservative MP Justin Tomlinson passed a confidential draft Public Accounts Committee (PAC) report to an employee of payday lender Wonga.

The incident occurred in 2013 when Mr Tomlinson, currently minister for disabled people, was a member of the PAC.

He has said he wishes to "apologise unreservedly" to the PAC.

Shadow Commons leader Chris Bryant said of Mr Tomlinson's case: "This now stands committed to the Privileges Committee for a decision on whether this is a gross contempt of the House - or at least it would do if the Privileges Committee had actually been set up by the Government."

Addressing Commons Leader Chris Grayling, the Labour frontbencher said: "So can you tell us why it has not yet been set up. Is it because the Prime Minister knew perfectly well this issue was coming along the track?

"When Lord Touhig was found to have asked for a draft copy of a select committee report some years ago, he immediately resigned as a (parliamentary private secretary) pending the decision of the then-Standards and Privileges Committee, who later suspended him from the House.

"Can you explain why the minister for disabled people has not done the same?"

The issue was revisited later after Mr Bryant raised a point of order, with Mr Grayling indicating work is ongoing to establish the committee and noting the body "clearly has some work to do".

Mr Bercow also said it was a fact the committee will have "substantial work" to do and "a certain urgency attaches to it".

He went on: "Some of that work hails from matters that came to the attention of this House, and much wider scrutiny in the media and elsewhere, up to four years ago.

"Therefore it is essential that that committee be established soon and I have every confidence the Leader of the House will expedite the matter without any further delay."