Before the vote, peers had for several hours debated the Rwanda agreement – and even addressed the prime minister’s comments last week.
Labour’s Lord Vernon Coaker said: “Nobody, not least the prime minister, should hold press conferences lecturing us about what our role is, when all we seek to do is to improve it and to act in our proper constitutional role.”
He added: “The government has not provided the evidence to support what it is saying needs to be done, either to the committee or to [the House of Lords].
“So how can we determine whether Rwanda is safe when the very things upon which that is dependent have not been provided to us? And that’s what the committee is saying.”
Lord Goldsmith, who was attorney general under Tony Blair, told peers that parliament cannot say whether Rwanda is “safe” because the steps contained in the treaty have not been introduced or shown to be functional.
The IAC report said, “some aspects of the monitoring arrangements under the treaty are unclear or incomplete”.
It also said the proposed monitoring committee that would watch over the system in Rwanda had “weak powers”.
On the other end of the spectrum, the Conservative former Foreign Office minister Lord David Howell criticised the “rather patronising tone one hears in some comments about Rwanda”.
Pointing out the nation was a member of the Commonwealth, he said: “I can understand the Rwandan government’s exasperation and that of senior legal figures at the implication that their system somehow has got to be reinforced, made over and renewed to bring it up to scratch and be called safe.”
But Liberal Democrat Lord Jeremy Purvis shared a story about how he believes he was “spied” upon after meeting with an opposition leader in Kigali, the African nation’s capital.
A Labour spokesperson said: “The government is desperately scrambling around to try and blame anyone else for their small boats chaos.
“This is a cross-party amendment with support from across the House of Lords which simply asks the government to properly implement the standards and safeguards over the Rwanda treaty that they are in theory committed to.
“It is fundamentally untrue to say that this measure blocks anything, they should stop blaming everyone else for their chaos.”
One Conservative peer voted against the ratification of the treaty – Alexander Scrymgeour, the 12th Earl of Dundee, who is a hereditary member of the Lords.
Downing Street said earlier on Monday that the government is still aiming to get flights off the ground this spring.