Jeremy Corbyn has insisted Labour with "keep on" with attempts to change the Brexit bill to give European citizens a guaranteed right to remain in the UK.
The Labour leader also urged members of the House of Lords to "stick with" their stance after they backed Labour amendments to the legislation that must be passed before Theresa May can formally trigger Brexit.
Members in the Lords voted through changes to the European Union (Notification of Withdrawal) Bill to guarantee protections for EU nationals living in Britain and for a "meaningful" parliamentary vote on the final EU exit package.
With these issues before MPs again on Monday, Mr Corbyn told the Press Association: "We will keep on with this."
He said: "There's key votes coming up on the right of European Union nationals to remain in the UK and on the final vote on the proposals.
"We put the same things at the committee stage in the Commons, we lost them there. We took them to the Lords, we won them both in the Lords by big majorities. We're now bringing it back to the Commons on Monday,
"Obviously I don't know the result any more than anybody does at this stage. Clearly to win requires all opposition parties to unite on this, that we seem to be able to do. But it also requires Conservative abstentions or votes with us on it.
"If the House of Commons does not pass then it goes back to the Lords and I hope the Lords will stick with that position and send it back to the Commons, because it seems to be an important message to put that EU nationals make a massive contribution to our society, in health, in education, in science and engineering, in agriculture, in so many ways.
"And they ought to be given the opportunity to remain in Britain. That would help to frame the future relationship with the EU after Brexit.
"If the Commons does not accept those Lords amendments it goes back to the Lords. If they persist it comes back to us a day or two later. We will keep on with this."