Peers have been urged not to insert further "terms and conditions" into the Government's negotiating position to leave the EU.

Brexit minister Lord Bridges of Headley told a packed House of Lords that now was not the time to "return to the fray" in the struggle over the Brexit Bill.

He said the legislation should pass unamended to allow the Government to get on with negotiations on quitting the EU.

But Liberal Democrat Lord Oates said the Government had failed to make concessions over the position of EU nationals living in the UK and called on peers to insist on changes.

His plea came after MPs cleared the way for Theresa May to formally start talks on Britain's divorce deal after overturning amendments previously passed by peers.

The House of Commons voted to reject two changes made in the Lords to the European Union (Notification of Withdrawal) Bill, which gives the Prime Minister the power to choose when to begin the two-year Brexit talks.

MPs voted against a proposal to unilaterally guarantee the rights of EU nationals living in the UK within three months by 335 votes to 287, majority 48.

They then voted against an amendment designed to give Parliament a "meaningful" vote on the final deal, by 331 votes to 286, majority 45.

As the Bill returned to the Lords, Lord Bridges said withdrawal from the EU was "one of the most momentous" steps the UK would take.

He said he was not "deaf to people's concerns" and did not dismiss them as "portraying a lack of patriotism", but the decision to quit the EU had been made and the Bill delivered on it.

The Lords was "perfectly entitled" to ask the Commons to think again and had done so, but once again MPs had decided to pass the Bill without amendment.

The issue at stake in the first amendment dealing with EU nationals in the UK was very simple: "We all agree we want to give certainty to those EU nationals who have made the UK their home and UK nationals who live in the EU."

The disagreement was on how to achieve this, he said. The Government had always said it wanted to secure the status of EU citizens in the UK, so long as the same guarantee was given to UK citizens in the EU.

Lord Bridges said an agreement was needed quickly, and the issue would be one of the first to be dealt with in the negotiations.

"That is why we want to pass this Bill as soon as possible, so we can start negotiating and set about reaching that agreement."

Given that the Commons had overturned the amendment, he said, tonight "isn't the time nor the place to return to the fray and insert terms and conditions to our negotiating position - still less to force the Government to make a unilateral move as regards the status of EU nationals in the UK".

Lord Oates said the Government had failed to make any concessions or attempted to address the many issues raised by peers.

The "profound nature of the issue" should make peers think very carefully before conceding, he said, calling for the Lords to reinsert the amendment.

Fear and misery were being caused by every day of uncertainty, Lord Oates said, insisting the decision was about the "integrity" of the UK.