The system around vetting former ministers when they enter new jobs to prevent a revolving door of appointments is “bust and needs fixing”, a peer has said.

Lord Pickles, chairman of the Advisory Committee on Business Appointments (Acoba), urged the Labour Government to make “long overdue” improvements to the rules within its first weeks.

In the foreword to a report covering the work of the vetting watchdog over the last four years, the Tory peer said there could be “no credibility” in a system that has “no demonstrable consequences or deterrent” for rule-breaking.

He said an efficient process is “fundamental to ensuring government benefits from the interchange of skills and experience between the public, private and charitable sectors, while protecting the integrity of government”.

Recent reforms have increased transparency and improved risk assessment, “but they can only go so far”, he said.

“The system is bust and needs fixing.”

Lord Pickles also said: “The public instinctively distrusts a system in which there are no consequences for even the most egregious breaches of the rules.

“A public reprimand and a couple of days of bad publicity for the miscreant only serve to underline how feeble the Government’s rules are.”

Last year, Boris Johnson was rapped on the knuckles by Acoba after he gave the committee only 30 minutes’ notice ahead of announcing that he was taking up a new role as a Daily Mail columnist.

It came a day after he became the first ever former prime minister to be found to have lied to Parliament in the report into his partygate denials.

But despite Acoba’s ruling that Mr Johnson committed a “clear breach” of the rules, the Conservative Government decided to take no further action against him.

Lord Pickles said on Thursday: “Improvements must include an enforceable system with options to meaningfully sanction individuals for egregious breaches.

“The system should operate on an exception basis, setting clear expectations up front for those in public office and encouraging a culture of proactive management of conflicts of interest.

“Some long overdue changes could be implemented in a matter of weeks without the need for legislation.”

Acoba stands ready to help Sir Keir Starmer’s Government to “take this opportunity to make impactful changes to the system,” he added.

The rules state former ministers must not take up new jobs or appointments for two years after leaving public office without advice from Acoba first.

A Government spokesperson said: “We are committed to restoring trust and ensuring government is in the service of working people.

“We share Lord Pickles’ concerns and have committed to reviewing and updating post-government employment rules and enforcing restrictions on ministers lobbying for the companies they used to regulate.

“We thank the committee for their report and the role they play helping to maintain standards in public life.”