I thought that was the whole point of the leaving bill - £35 Billion- to pay for the pensions that the UK voted for over the years that we were a member of the EU. I do not know why we didn't suggest we would pay our own Members fully out of the normal pension bill only and not contribute to all the others.
By the way it has all gone very quiet on the negotiations, which forecasts a result which I would be very much against. It looks likely I will be firing off an e-mail to my MP,