This Monday, Boris Johnson got his controversial domestic market law to pass its first test in the British Parliament. With the support of 340 deputies and the rejection of 263, Johnson asserted the absolute majority with which he has in the House of Commons.

However, he did not manage to stop the growing chorus of voices, in the opposition and within his own party, who denounced that the bill violates international law, by challenging an international treaty such as the agreement of the brexit. In the document signed by the United Kingdom and the 27 member states of the European Union, it is established that that agreement supersedes any British national law on the subjects stipulated in the treaty. Now, if Johnson succeeds in passing this law, he would be violating an international treaty.

The rule would break the call irish safeguard, which seeks to avoid the creation of a physical border between the two Irish, the only land border that the United Kingdom will have with the EU. The agreement of brexit removes the whole of the UK from the customs union, but still leaves Northern Ireland within EU rules, especially for goods, to ensure that everything coming from the UK to EU consumers complies with the quality requirements of the single market. The new law could remove those controls.

In addition, the agreement of brexit It foresees that European taxes will be applied to goods that, traveling from Great Britain to Northern Ireland, have the EU countries as their final destination, but Johnson wants the United Kingdom to define what type of goods will be subject to these conditions.

In the debate prior to the vote, Johnson intervened to defend the text on the grounds that it is a “safe” to prevent Northern Ireland from being commercially detached from the rest of the country if London and Brussels fail to agree on their future relationship before the December 31 deadline.

In the event that a pact is finally reached, “the powers that the law grants to the Executive would never be invoked,” said the head of government, who still sees consensus as possible. Without an additional “safeguard,” he argued, Brussels could reach block trade between that British region and the rest of the UK in case of a brexit abrupt at the end of this year.

However, critics of the rule – both the opposition and members of its own ranks – point out that this could put the UK’s credibility with countries with which it can agree on future trade relations. If Johnson is willing to violate an international treaty, who would trust him to reach some kind of agreement?

In recent days were his predecessors in Downing Street Theresa May and John Major who showed their rejection of Johnson’s plan, and this Monday the conservative prime minister joined David cameron, which called the referendum on the brexit, and his own Minister of Economy until February Sayid javid.

The initiative has not sat well in Brussels and the European Commission threatens to take the UK to court if there is no change of position until the end of the month. “For there to be a relationship between the UK and the European Union in the future there must be mutual trust“wrote Michel Barnier, the EU negotiator, after the eighth round of negotiations.

Also the president of the European Commission, Ursula von der Leyen was “concerned” by the “intention” of Reino Uido to “violate the exit agreement”.

The real test for the law will come next week, when the amendments to the provisions on Northern Ireland, the origin of the violation of what was agreed with the EU, are scheduled to be voted on.