I think actually it's the EU saying that. They've accepted it long ago and just want to know what we're actually doing so they can prepare either way. There's no reason for them to make concessions from a deal that works for them just so Boris can slap it on a lunchbox and call an election. All he's succeeding in is hurting the pound and giving more ammunition to the SNP
The pounds hardly changed recently (pretty much what it was a week ago). I agree that the EU won’t agree to significant changes but I’d happily have a tenner on them moving on the backstop mechanism if Boris gets through the next few days. That will be sufficient, in conjunction with the only alternative being No deal, to get the WA through Parliament.