The European Commission is to send a “letter of formal notice” to Boris Johnson’s government for breaching the terms of the Withdrawal Agreement over Brexit.
The UK government has signalled it could tear up elements of the package relating to Northern Ireland in the Internal Market Bill, which cleared the Commons this week.
The European Union had called for the UK to withdraw the elements of the legislation which would breach international law by the end of September.
Von der Leyen said: “We had invited our British friends to remove the problematic parts of their draft Internal Market Bill by the end of September.
“This draft bill is, by its very nature, a breach of the obligation of good faith laid down in the Withdrawal Agreement.
“Moreover, if adopted as is it will be in full contradiction of the protocol on Ireland/Northern Ireland.
“The deadline lapsed yesterday, the problematic provisions have not been removed.
“Therefore this morning the commission have decided to send a letter of formal notice to the UK government. This is the first step in an infringement procedure.”
The legal letter is the first step in a a legal process that could result in a lawsuit at the European Court of Justice.
The EU has given the government a month to send its response.
“The commission will continue to work hard towards a full and timely implementation of the Withdrawal Agreement,” she said.
“We stand by our commitments.”