Parliament is not adequately holding Tony Blair to account, a powerful cross-party group of MPs has concluded.

The Public Administration committee says that the once-weekly session of prime minister's questions, which is dominated by a clash between Tony Blair and William Hague, is not an "adequate or sufficient" forum through which to scrutinise the work of the prime minister.

In a bid to tackle the problem, MPs propose that Tony Blair should in future endure an annual grilling by the chairmen of select committees where he could be probed in detail on the government's performance.

They also call for greater regulation of ministerial contacts with the lobbying industry and increased powers for parliament's sleaze watchdog. Following the Derek Draper affair, in which it was claimed lobbyists had special access to some ministers, the MPs call for the code to be revised to introduce a system to monitor ministers' relations with lobbying groups.

The report states: "We agree with Lord Neill that the accountability of, and public confidence in, ministers would be strengthened if external contacts of this kind were recorded."

The comments come in a report entitled "The Ministerial Code: Improving the Rule Book" which was published by the committee on Wednesday. The MPs conclude: "The ministerial code matters - and not just to constitutional anoraks. It sets standards for ministerial conduct. It has just grown like Topsy over the past half century and it is now time to put it on a proper footing and to give it more coherence."

The report also rebukes the government for announcing policy outside parliament. It calls for the restoration of a rule that "when parliament is in session, important announcements of government policy should be made, in the first instance, in parliament".

The recommendation follows increased anger on the opposition benches at government attempts to bypass the Commons by announcing new policy initiatives in set-piece speeches outside parliament and on early morning radio and TV programmes.

The committee also calls for the ministerial code to be given greater recognition and its status as the bible for regulating ministerial conduct to be formalised.

"It is the rulebook for ministerial conduct and its status should reflect its importance. It may have developed in a private and ad hoc way, but it is now an integral part of the new constitutional architecture. It is time for it to be recognised as such," the MPs say.

The committee agreed that the prime minister should remain in charge of the code, but has called on this fact to be "explicitly acknowledged" to ensure that the lines of accountability are made clear. "The code is the prime minister's document and it is with the prime minister that the buck must finally stop," the report argues.

The prime minister last year refused to give evidence to the inquiry, although his predecessor, John Major, went before the cross-party committee of MPs. Blair said that by convention prime ministers did not appear before select committees.

The report also recommends that the remit of the parliamentary commissioner for standards is extended to allow the commissioner to give advice on the code to ministers. It also calls for the parliamentary ombudsman to be given the power to investigate alleged breaches of ministerial rules and the creation of a free-standing code of ethical principles to be devised.