Downing Street is running a structured intelligence-gathering operation on the viability of promising EU re-entry. Senior officials have been reaching out to thinktanks and pollsters — including the Tony Blair Institute, Best for Britain, IPPR, and Think Labour — to test whether a rejoin pledge could survive a general election campaign without resurrecting Reform UK's relevance. The effort is more advanced than the official line suggests. Some at the top of government wanted Andy Burnham to promise in his conference speech to begin rejoin negotiations after the next election, not merely launch a review. That option was killed because the party was already absorbing the political cost of pension reform and didn't want to hand Farage a second front. No 10 denies the promise was ever in any draft of the speech. The evidence base being assembled is substantial. Best for Britain commissioned a YouGov megapoll suggesting Labour could more than double its seat count with a rejoin pledge. The Tony Blair Institute published a conditional framework: rejoin, but only if Brussels loosens regulation in energy and technology. IPPR will release a paper calling for full re-entry in the coming weeks. This isn't organic — it's coordinated signal-testing. The Farage calculus dominates internal debate. Some officials are buoyed by polling showing a rejoin promise does little to boost Reform support. They note Farage attacked the pensions triple lock changes, not the Europe comments — suggesting the issue may not be the electoral landmine it was in 2019. Others remain deeply nervous that any formal rejoin commitment would give Reform its founding narrative back. Brussels is cautiously receptive. Emmanuel Macron said "Welcome back" in English at a Madrid press conference. An EU spokesperson offered the standard diplomatic formula — "open to engaging" — but the real signal is operational: talks of holding the UK-EU summit on 20 November have resumed after Burnham's speech, having previously been threatened by disputes over Made in Europe legislation. One diplomat distinguished between concluding Starmer's old reset and beginning "a real reset." The Made in Europe dimension is the underreported lever. No 10 has been trying to get British manufacturers classified as European for procurement purposes — a concrete trade interest that gives the rejoin conversation economic teeth beyond abstract growth arguments. The linkage between the political signalling and the trade negotiation is where this story has real structural weight. What's happening is a phased political operation: review first, evidence accumulation second, manifesto commitment third — if the numbers hold. The 20-year question is whether this represents a genuine structural reorientation of UK trade and regulatory policy or another cycle of European ambiguity that leaves businesses unable to plan.