By William James
LONDON (Reuters) - Prime Minister Theresa May's Brexit plans face rejection by parliament's upper chamber on Monday, setting the stage for a confrontation with pro-EU rebel lawmakers later in the week which could rock her minority government.
Ministers are seeking approval for the final wording of the legislation that will end Britain's membership of the European Union next year. However, they have fallen into a row with lawmakers from May's Conservative Party who want parliament to have a say in the exit process if talks in Brussels fail to reach an acceptable divorce deal.
That threatens May's authority over her divided party, and underlines the balancing act she has to pull off to keep onside those who want a "softer" Brexit, without upsetting those in favour of a clean break with the EU.
"We have been listening to the role of parliament. But we need to make sure that parliament can't tie the government's hands in negotiations, and can't overturn the will of the people," May said on Monday
Sometime after 1400 GMT, the House of Lords will debate different proposals for a "meaningful" vote - the role parliament will play if lawmakers reject a deal that May negotiates with the EU, or if she fails to agree any exit deal.
Talks between May and the pro-EU rebels on a compromise plan broke down last week at the last minute.
Ministers have so far agreed to give parliament a symbolic vote on the government's strategy if its initial exit deal is rejected, but not to give lawmakers the power to force changes.
Speaking before the vote, foreign minister Boris Johnson reinforced the government's view that discussion of the meaningful vote was hypothetical as ministers were confident of getting a deal with Brussels that parliament will approve.
"We are absolutely confident that we will deliver a Brexit deal that ... would be good for the UK, good for our European friends and partners. We're going to get on and do it," he told reporters.
The rebels are holding out for more assurances, warning that they could bring down the government. Ministers are digging in and refusing to give ground for now.
A spending pledge for Britain's public health service by May has also irritated some pro-EU lawmakers, who question the government's assertion that the new funding is part of a "Brexit dividend" - money saved by leaving the bloc. Independent official figures endorsed by the Treasury show that leaving the EU will actually cost money, not save it.
May's Conservatives do not have a majority in the unelected House of Lords, and with the opposition Labour Party deciding to back a rival proposal, the Lords are expected by early evening to reject the government wording on a "meaningful vote".
That would tee up a showdown when the bill returns for a more decisive vote in the elected House of Commons on Wednesday, where May's minority government can afford to lose no more than a handful of Conservative rebels.
This will be crucial for May's attempts to resist a move seen as a step towards a softer Brexit, meaning closer ties to the EU on issues such as customs and regulations.
Failure to keep her party in line would signal trouble for several other contentious pieces of legislation needed to prepare for Brexit, including on central issues such as trade and customs policy.