1/ Would the UK have to pay more into a larger EU budget to subsidise the bloc's response to coronavirus if the transition is extended, as claimed by No 10? The short answer, EU sources say, is no. There is no direct link between the transition payment and the size of the budget.

2/ Here's our old friend Art 132 of the Withdrawal Agreement again, making clear the UK will be outside the EU's next long-term budget (MFF). So the transition payment would not be based on the UK's current contribution to the EU budget and the rebate doesn't come into it either.

3/ Instead it might be more constructive to look at how Norway pays into the budget. It pays into specific EU programmes it wants to be part of and contributes a hefty whack to the cohesion fund. In all it stumps up two-thirds per person what the UK does. https://fullfact.org/europe/norway-eu-payments/

4/ Of course the situations aren't exactly like for like (Norway isn't in the Customs Union, for one) and if the UK were to agree to an extension there would have to be a political negotiation on the amount it would pay. Uncharted territory for both sides, and a tight timeframe.