Irish Prime Minister Leo Varadkar said Britain had been offered “reassurance and guarantees” over the Brexit deal as MPs in London prepare to vote Tuesday on whether to accept the withdrawal agreement.

But Varadkar denied that a last-ditch Strasbourg summit between British Prime Minister Theresa May and European Commission president Jean-Claude Juncker on Monday had brokered alterations to the so-called Irish backstop.

Changes to the mechanism  designed to guarantee the continued absence of a hard border on the island of Ireland are a key demand among those British MPs blocking the withdrawal deal.

“The further texts agreed yesterday provide additional clarity, reassurance and guarantees sought by some to eliminate doubt or fears, however unreal, that the goal of some was to trap the UK indefinitely in the backstop,” said Varadkar.

“It is not. These doubts and fears can now be put to bed.”

Varadkar said the legal instrument agreed in Strasbourg “does not call into question that the backstop will apply unless and until better arrangements are agreed.”

“Brexit has been a dark cloud over us for many months, and particularly the threat of no deal,” he said.

“A positive vote tonight can remove that cloud and restore confidence and optimism in Britain, Ireland and across the European Union.

“We now need to see the withdrawal agreement ratified by Westminster and by the European Parliament without further delay, so that we can get on with the important work of building the closest possible relationship between the EU and the UK, and between the UK and Ireland, post Brexit.”

In January British MPs voted overwhelmingly to block May’s withdrawal deal in a historic defeat for the beleaguered prime minister.

Key factions in her own party, as well as allies in Northern Ireland’s Democratic Unionist Party objected to the backstop required to keep the Irish border open — a key component of a 1998 peace deal on the island.

The backstop would tie the UK in a customs union with the EU, with further alignment to EU standards for Northern Ireland, “unless and until” another relationship is forged.

Objectors believe that may leave Britain in limbo if such a relationship cannot be agreed on.