European Commission President Ursula von der Leyen on Thursday said it had sent a letter of formal notification to the U.K. over its arrangement to abrogate the Brexit divorce from deal, denoting the first step in legal proceedings.

It comes after U.K. officials affirmed Prime Minister Boris Johnson’s questionable Internal Market Bill prior this week, in spite of certain priests conceding the legislation could prompt the nation breaching international law.

The U.K. has said the proposed legislation, which presently requires the approval of the House of Lords, will secure the integrity of the U.K. The bill would permit ministers to unilaterally amend elements of the nation’s Withdrawal Agreement with the EU.

It has enhanced divisions between the U.K. also, Europe, taking steps to scupper trade talks during the post-Brexit transition period.

“If adopted as is, it will be in full contradiction to the protocol of Ireland-Northern Ireland,” Von der Leyen said in a televised statement.

The top of the EU’s executive arm said it had given Britain until the finish of September to eliminate “problematic parts” of the Internal Market Bill, however the deadline had now passed and the arrangements remained.

“Therefore, this morning the Commission has decided to send a letter of formal notice to the U.K. government. This is the first step in an infringement procedure.”

The U.K. government will have a month to answer with its “observations,” von der Leyen said. “Besides this, the Commission will continue to work hard towards a full and timely implementation of the Withdrawal Agreement. We stand by our commitments.”

The EU has previously said the Internal Market Bill constituted an “extremely serious violation” of the Withdrawal Agreement. It has likewise cautioned it would “not be shy” in using all accessible legitimate methods if the U.K. failed to amend the bill in its present form.