The European Union said it won’t abandon trade talks with the U.K. even if Boris Johnson’s government doesn’t withdraw its plan to break international law.

Yet at the same time, the bloc renewed its threat to take legal action in a sign of just how delicate negotiations are as the clock ticks on a compromise.

European Commission Vice President Maros Sefcovic, who held talks with U.K. Cabinet Office Minister Michael Gove in Brussels on Monday, said the EU would never pull out of negotiations on a future relationship despite the U.K.’s attempt to rewrite parts of the Brexit divorce treaty signed last year.

He said Gove hadn’t assured him the government would back down so he “will not be shy” in looking at legal proceedings, but declined to say when or what they would be. The EU’s deadline for the U.K. to change tack is two days away, in the middle of the final negotiating round on a wide-ranging future trade and security partnership.

The comments highlight how the two sides are involved in a delicate balancing act.

While, the EU objects to the U.K. plan and it has increased the lack of trust in Johnson’s government, the bloc is determined to get a trade deal. Likewise, British negotiators are still optimistic of finding agreement and don’t want the row over the divorce treaty to wreck things.

“We have seen it as a breach of trust” but “we are determined to get a deal,” Sefcovic told reporters. “It will never be the EU that will cause the end of the negotiations on the future partnership.”

Monday’s meeting was arranged after the U.K. government earlier this month published a draft law that would unilaterally rewrite parts of last year’s withdrawal agreement aimed at avoiding customs controls between Northern Ireland and the Irish Republic.

Sefcovic said the deal “is to be implemented, not to be renegotiated—let alone unilaterally changed, disregarded or dis-applied.”

The talks came at the start of a week of intense negotiations as the two sides race to get a trade deal within the next few weeks. The government’s acknowledgment that the Internal Market Bill would break international law has cast a huge shadow over those talks as time ticks down to the mid-October deadline for an agreement set by Johnson.

In a televised statement, Gove said the controversial clauses in the bill won’t be cut because they are designed to be a “safety net.” He said he was hoping to negotiate a settlement with the EU.

Johnson’s spokesman James Slack said the British prime minister still considers Oct. 16 the final date for an agreement and said the EU needs to adopt “more realistic” policy positions.

The U.K. has said the Internal Market Bill is necessary because of the need to claw back sovereignty after Brexit and not risk the breakup of the U.K. Under the divorce agreement, which Johnson signed with the EU in November, Northern Ireland would remain in a customs union with the bloc, with some checks on goods between it and the rest of the U.K.

The EU said that was necessary to protect peace in Northern Ireland by preventing any checks on the Irish border. The issue has now become a matter of trust, with the bloc’s negotiators increasing their demands for enforcement of any future trade deal.

Negotiations on the trade deal continue from Tuesday.