THE government is being challenged by 12 trade unions over its controversial change in the law to allow firms to hire agency workers to replace strikers.

Thompsons Solicitors has written to Business Secretary Kwasi Kwarteng on behalf of the unions claiming the new regulations are a violation of Article 11 of the European Convention on Human Rights.

It also claimed that the new regulations violate the EU-UK Trade and Co-operation Agreement, which commits Britain to respecting, promoting and implementing internationally recognised core labour standards, including those relating to freedom of association and the recognition of the right to collective bargaining.