Ministers who breach the rules on post-government jobs could be hit by financial sanctions under a new ethics scheme that has been criticised for falling short of a drastic overhaul.

Deputy Prime Minister Oliver Dowden announced a range of reforms in response to critical reports on lobbying rules and standards in public life after a series of scandals.

Though “progress” was cautiously welcomed, transparency campaigners made clear the reforms do not meet the “fundamental upgrade” they say is required.

Lord Evans, chairman of the Committee on Standards in Public Life, said it was regrettable that some of his key recommendations to tackle sleaze in Westminster had not been adopted.

Labour described the changes as “far too little, far too late”.

One major change was designed to prevent breaches of the Advisory Committee on Business Appointments (Acoba) rules, as Boris Johnson has recently been accused of.

A “ministerial deed” will be designed to legally commit ministers to the rules on accepting jobs after they leave office, binding them by the same restrictions as civil servants.

The ethics report published by Mr Dowden on Thursday said a tightening of the rules could include further sanctions including “financial penalties” for breaches.

New transparency guidance will mean stricter standards for the description of meetings, and departments will be required to disclose diarised phone calls and virtual meetings.

Lobbying rules will be tightened, forcing departments to declare official business discussions on WhatsApp, private email and by text message.

But a raft of recommendations posed by Lord Evans and Nigel Boardman, who conducted a review into the Greensill Capital lobbying affair, were rejected.

A possible five-year ban on ministers taking up lobbying roles was dismissed and a comprehensive strengthening of the lobbying register was dismissed.

Laws will also not be brought forward enshrining the roles of ministerial interests adviser, public appointments commissioner and the Acoba body.

Lord Evans warned that while “progress has been made”, the reforms “should not be the end of the story”.

He said that “regrettably” ministers had not agreed with suggested changes to the power of the ministerial interests adviser, the status of the Ministerial Code or calls to put ethics bodies on a legal footing.

In a blog post, the peer said: “We would encourage the government to keep the remainder of our recommendations under review. The rules that govern public office require constant attention.”

Acoba chairman Lord Pickles welcomed the changes, but said that reforms needed to be introduced “quickly and incrementally”.

He said that such an approach was necessary given that the Government had rejected calls to give the appointments watchdog a legislative footing.

Alastair McCapra, chief executive of the Chartered Institute of Public Relations, said there were “tweaks in the right direction” that should be applauded.

“However, ultimately it falls short of the wholesale reform needed to restore trust in the integrity of our political institutions,” he added.

“These new rules fail to provide a level playing field for the lobbying profession. Until we have a register that captures lobbying activity rather than who is doing the lobbying, we will not have true transparency.”

Deputy Labour leader Angela Rayner accused Prime Minister Rishi Sunak of having chosen to “preserve the worst parts” of the “rotten ethics regime at the centre of Tory sleaze”.

“These proposals barely scratch the surface of the problem, and fail to address the majority of proposals put forward by the regulators,” she said.

Dr Susan Hawley, executive director of the Spotlight on Corruption campaign, said that less than half of the Boardman and Evans recommendations had been accepted and nearly a third had been rejected outright.

“While increased transparency in lobbying is both welcome and long overdue, as are new rules to tackle the revolving door, the Government has rejected crucial recommendations about protecting the independence of regulators through their appointment processes, giving them powers to initiate investigations, and giving them a statutory footing,” she said.

“As Lord Evans has put it, overall these are repairs, rather than the fundamental upgrade of the standards system that is so desperately needed.”

Labour called the changes “far too little too late”.

Deputy leader Angela Rayner said: “These proposals barely scratch the surface of the problem, and fail to address the majority of proposals put forward by the regulators.”