When Boris Johnson and Priti Patel first launched the Rwanda scheme, in the Spring of 2022, there seemed every chance that it could win the Tories the next election.

Despite the ‘Partygate’ furore taking chunks out of the Conservative poll rating and ushering in a febrile atmosphere, Labour was struggling to create a large and durable poll lead.

Exactly two years ago, the Politico website’s poll of polls had the Labour lead at just four points and Keir Starmer’s party was highly vulnerable to a Tory fightback based around the touchstone issue of tackling illegal immigration.

These days the poll gap is so vast that not even the most Tiggerish Tory optimist would dare talk about Rwanda being a potential springboard to victory. But equally it would be wrong to conclude that the spectacle of some planes being occupied by some failed asylum seekers finally taking off for Kigali would make no difference.

This is the context in which we must interpret the goings on in the House of Lords last night, where peers voted to reinsert seven amendments to legislation which seeks to declare Rwanda a safe country and insulate the removals process against extended legal challenges.

The effect of the Lords necessitating at least one more round of parliamentary ping pong is to delay the Bill’s passage to beyond Easter and the prospect of flights beginning until the very end of Spring at the earliest.

During the interim, there is every chance of Channel crossings running at a level matching that of 2023 – around 500 migrants were brought into Dover only yesterday – further shredding Rishi Sunak’s key pledge to ‘stop the boats’ and further stoking public hostility towards his party.

Lord Coaker, a veteran Labour machine politician now serving as Home Affairs spokesman in the Lords, complained to peers yesterday that the Bill had come back from the Commons in its original form, with all of their initial ten amendments removed: ‘Without a single word changed, not a single comma moved or a single full stop inserted.’

‘It is not our intention to block the Bill,’ he added, accusing the Commons of ignoring a ‘constitutional convention that the other place reflects on what your Lordships have said and does not just carte blanche reject it’.

When such expressions of high-mindedness are to hand one can be sure that low politics is lurking in the shadows.

Despite characterising the Rwanda scheme as a prohibitively expensive gimmick and pointing out its limited capacity of just a few hundred places in the first year, perhaps as few as 200, it remains the case that Labour is deeply nervous about it getting underway.

That’s largely because senior Labour figures do understand that the intended deterrent effect of the scheme might just work, at least in the short term.

Consider the following possible scenario: a flight goes to Rwanda with just 50 migrants on board. Ministers announce that from this point onwards future flights will be entirely devoted to new Channel crossers. Word spreads through the camps in northern France that whoever is in the next three boats to cross can expect to be fast-tracked to Rwanda. So nobody wants to be in the next three boats and therefore nobody will pay a people trafficker for a seat in one.

The effect could easily be to ‘stop the boats’, at least for a while until the remaining avenues for legal attack against the legislation, identified by Robert Jenrick and others, are fruitfully exploited by immigration lawyers.

This would put Starmer’s party in a very sticky situation. Against all expectations, Sunak would be seen to have driven through legislation under sustained fire from Labour, the Lords, the Blob etc. which had a positive initial effect on a hugely emotive issue.

It would certainly give grounds for any disenchanted Tory looking for an excuse to hold his nose and vote Conservative again to decide to do so. Throw in somewhat better economic times and under this scenario, Labour’s average lead could drop from 20 points to 12, triggering panic in its upper echelons. Starmer and Yvette Cooper, who have said they will scrap the Rwanda scheme even if it is up and running, would have egg all over their faces and come under huge pressure to change their minds.

Such a major switch in the political narrative is to be avoided at all costs as far as Labour is concerned. This is why they are playing it long and why Lord Coaker is adopting the persona of a maiden aunt who has just been exposed for the first time to a post-watershed TV drama.

It would be wrong to say there is all still to play for. But Rwanda, far more than national insurance cuts or even falls in inflation, still has the potential to shift significant numbers of voters back into the Tory column.