It has been hailed as a victory and also as a humiliating defeat for the British government. On Tuesday the House of Lords voted 358 to 256 to amend the Article 50 Bill by including a clause to safeguard the rights of EU nationals in the UK after Brexit.
In a statement issued after the vote, the government described the result as "disappointing" but it has indicated that it intends to overturn the result when the Bill returns to the House of Commons and that prime minister Theresa May is determined to trigger Article 50 by the end of March, as planned.
The discussions in the House of Lords were polite but quite heated at times, especially when Lord Tebbit asked: "Why is everybody here today so excited about an amendment which looks after foreigners and not the British?", apparently not bearing in mind that British nationals living in other EU countries are also foreigners and also face uncertainty about their future. Other peers had stressed that EU nationals had come to the UK in good faith and were contributing to the country's prosperity, but had not been able to vote in the referendum.
Prime minister Theresa May has been under pressure to guarantee the rights of EU nationals who are already living and/or working in Britain post-Brexit, but she is reluctant to do so without a reciprocal guarantee in place from other EU governments.
Peers who voted for the amendment to Article 50 are now hoping to persuade Conservative MPs to defy the whip and support the amendment, although it is thought unlikely that many will do so.
Next week the Lords are due to vote on another proposed amendment to give MPs a meaningful vote on Mrs May's negotiations with the EU, and there is a strong possibility that the government will also be defeated on that.