European courts will continue to "dish out judgments" to Britain if the UK opts for a transitional deal after Brexit, an influential EU leader has warned.
The comments from Malta's prime minister Joseph Muscat, whose government holds the rotating presidency of the EU for the first half of this year, come after Theresa May pledged to take the UK out of the jurisdiction of the European Court.
The Maltese premier made clear than any transition trade arrangements, which could last well into the 2020s, would see European institutions retain the upper hand.
"An essential part of those transitional arrangements will be the governing institutions of that period," he said, according to The Times.
"It is pretty clear to me that the institutions should be the European institutions.
"So it is not a transition period where British institutions take over, but it is a transition period where the European Court of Justice is still in charge of dishing out judgments."
Malta's finance minister Edward Scicluna said he believed the Prime Minister would "blink first" as pressure grew during exit negotiations.
Mrs May, who will deliver a key-note Brexit address next Tuesday, told last autumn's Tory conference: "We are not leaving only to return to the jurisdiction of the European Court of Justice."
The Prime Minister will be under pressure to use next week's speech to spell out a broader strategy ahead of triggering formal divorce negotiations, which she has promised by April.
Reports have suggested Mrs May will commit to pulling out of the single market if the European Union fails to make concessions on the free movement of its citizens, although they have been dismissed as speculation.
Foreign Secretary Boris Johnson and Brexit Secretary David Davis are contributing to the content of the address, which opposition parties hope will end months of secrecy over the Government's exit plans.
Meanwhile, the Supreme Court is expected to rule this month on whether Mrs May has the authority to invoke Article 50 without the prior consent of Parliament.
It the court rules against the Government, ministers will have to prepare legislation and pass it through the Commons and the Lords before the end of March to stick to Mrs May's Brexit timetable.
Mrs May's official spokeswoman said: "She will be making a speech on Tuesday, setting out more on our approach to Brexit, as part of preparing for the negotiations and in line with our approach for global Britain and continuing to be an outward-looking nation."