Theresa May’s letter to Jeremy Corbyn last night has certainly divided opinion. Was it a dastardly move to keep open the option of a soft Brexit (via a customs union), as Jacob Rees-Mogg and other Brexiteers seem to think? Or was it actually just a bit more window-dressing by a PM who has no intention of working with Corbyn but wants to be seen as reaching out?Well, suspecting the PM of bad faith these days is almost an Olympic sport on all sides at Westminster, but perhaps what matters most here is that some key Labour people I’ve talked to are firmly in the latter camp. They think May’s letter underlined her red line, while trying to argue ‘a customs union’ was not needed because her political declaration on future UK-EU trade would sort it all out. “It’s a vague series of non-commitments, we can’t sign off on a blind Brexit,” one source says. Rather than a genuine pitch to Corbyn, May’s letter felt more aimed at offering fresh comfort to those Labour backbenchers in Leave seats whose votes she needs to get her deal through. All the talk of legislation on workers’ rights, ‘further financial support’ to communities ‘left behind’, compromise on. EU agencies and even security co-operation (see below) was designed to maintain and even expand the number of MPs thinking of backing her plans. As ex-minister Sam Gyimah put it on Radio 4 last night, it felt like the PM was trying to “promise everything to everyone in the hope that we all clamber aboard the good ship May.”This Thursday’s Valentine’s Day vote will be another test of whether May’s strategy of running down the clock succeeds. An amendment seeking to bring back the second ‘meaningful vote’ by February 26 will get Labour backing, but it’s unclear how many Remainer Tories will be on board. If the amendment is non-binding, it could be an irrelevance anyway. This morning on Today, Boris Johnson tried to keep a high bar on his own support for the PM, saying a legally binding ‘time limit’ on the Northern Ireland backstop would “not be good enough”. A “UK-sized exit” that allowed us to “get out by our own volition” was as crucial, he said. And he sounded happy for the clock to tick away.