Foreign embassies in London are to be hit with a crackdown on “modern-day slavery” and other alleged employment malpractices, the Evening Standard can reveal.

The law will be tightened so that countries are no longer able to claim immunity from being taken to an employment tribunal by “domestic workers” including chefs, cleaners, nannies and security staff working for diplomatic outposts in Britain.

The move comes after a Supreme Court ruling that two parts of the 1978 State Immunity Act (SIA) are not compatible with the European Convention on Human Rights. The Government said it was aware of around 55 employment claims against diplomatic missions in London that were “working their way through courts”.

Twelve others had been decided as of May this year. The Foreign Office added that 30 countries had “claimed immunity” including Algeria, Angola, Bahrain, Brunei, Burundi, Cyprus, Denmark, Egypt, France, Ghana, Guyana, Haiti, India and Kenya. As had Kuwait, Libya, Malaysia, Myanmar, Nigeria, Qatar, Saudi Arabia, South Africa, Spain, Trinidad and Tobago, Yemen and Zambia.

The Government is now set to push through Parliament a “remedial order” to address the legal flaws in the 1978 Act which will mean countries will no longer be able to thwart employment tribunal moves by using immunity.

Nickie Aiken, Tory MP for the Cities of London and Westminster, where many embassies are located, said: “There is no place in this country for any form of modern-day slavery practice. To think that it may be happening behind closed doors in embassies in the heart of London is shocking and appalling.”

Sir Stephen Timms, chairman of the Commons work and pensions committee and Labour MP for East Ham, added: “People living in Britain, irrespective of their employer, are entitled to the protection of the law which applies to everyone.”

The 30 nations listed have not broken UK law and may dispute allegations against them of employment malpractices, particularly modern slavery, and tribunals may find in their favour.

But the 1978 Immunity Act prevents this group of domestic staff seeking redress in Britain if they believe they are victims of flawed employment practices. The remedial order will limit this state immunity to cases which might be brought by diplomats, consular officers or other people employed on a “sovereign authority” or “governmental” basis.

Parliament’s Joint Committee on Human Rights this week backed a draft version of the State Immunity Act 1978 (Remedial) Order 2022 which is now expected to go to the Commons and Lords for approval early next year.

The committee highlighted the two cases which have led to the proposed legal change. Fatima Benkharbouche, a Moroccan national, was recruited in Iraq and employed as a cook in the Sudanese embassy in London.

She made an employment tribunal claim for various workplace issues including unfair dismissal, failure to pay her the minimum wage, unpaid wages and breaches of the working time regulations. The second individual, Moroccan national Mina Janah, was recruited in Libya and employed as a nanny at its embassy in the capital.

She made an employment tribunal claim for various breaches of workplace law including unfair dismissal, discrimination and harassment. The majority of both claims were dismissed in the lower courts on the basis that the employers were immune but their cases were then heard by the Supreme Court and European Court of Human Rights.