Ministers have been accused of chaotic handling of a post-Brexit regime for recognising the qualifications of foreign professionals, intended to help make Britain “the best place in the world to work”.

The government introduced the professional qualifications bill into parliament without fully realising which professions would fall within its scope.

Baroness Sheila Noakes, a Conservative peer, said the bill had the hallmarks of one “conceived and executed by officials with little or no ministerial policy direction or oversight”. She said it was “no way to legislate”.

Lord Gerry Grimstone, business minister, has admitted that the government’s handling of the legislative detail was “not good enough” and that he felt “uncomfortable” listening to criticism of it.

Having previously listed 160 professions and 50 regulators affected by the legislation, Grimstone has published a revised list of almost 200 professions and almost 60 regulators.

Professions that have been added include acute internal medicine and intensive care medicine, while regulators include the Legal Services Board and the Institute of Chartered Accountants in England and Wales, and its equivalents for Scotland and Northern Ireland.

“I accept, without reservation, that it is not good enough that these lists have been incomplete,” he told the House of Lords last month. He said peers “must have felt they were playing a game of blind man’s buff in trying to see who the bill applies to”.

The legislation replaces the EU regime for recognising the qualifications of professionals coming to work in the bloc with a new post-Brexit system for the UK.

The government said the legislation would “further strengthen UK professions’ reputation for excellence and help to ensure the UK can address where the demand for skills is not currently met”.

The new law would allow foreign professionals to have their qualifications recognised in Britain where they met UK standards, with regulators given autonomy to assess those qualifications and seek reciprocal deals.

Prime Minister Boris Johnson has promised a post-Brexit immigration system to attract the “brightest and best” global talent, but ministers have struggled to frame the new law to cover all relevant professionals.

“It is baffling that this legislation has been introduced without the government knowing which professions or regulators are covered,” Baroness Dianne Hayter, a Labour peer and shadow business minister, said.

The Labour party said that if the legislation was not “fit for purpose” by the time it reaches its report stage in the House of Lords, then it could be amended by peers working across party lines.

Business department officials admitted that the legislation had evolved in an “iterative” fashion and Grimstone admitted that trying to draw up a British regime had proven problematic.

He told peers this month: “What has come to light, frankly, during this process, is that not all regulators have a copy of the list of the professions which they regulate.”

Helen Brand, chief executive of the Association of Chartered Certified Accountants, said the bill would be “a catalyst to future free trade agreements”, particularly in relation to mobility and trade in services.

The business department said the legislation would “revoke the current, outdated EU system for recognition of professional qualifications, establishing a new approach based on regulator autonomy as well as supporting UK professionals to deliver services overseas”.