Philip Hammond has been asked by the Treasury Committee about whether there will be a Brexit deal dividend.
If there is a "good deal" business confidence could rise and consumers have the confidence to spend, the Chancellor said.
" It would be choice, say in 2021 if we had a deal agreed, signed and sealed everybody was happy, business confidence was rising, it would be a choice.. in 2021 whether to maintain £15bn of
headroom to the fiscal rule or whether to borrow a little more and put a little
more into the spending review. That would be a choice we could make".
He added that the UK would not be sending £9bn or £10bn a year to Brussels and the OBR had assumed this would be spent on items that the EU would be doing, such as agriculture.
He defined a good deal as one that involved frictionless trade continuing.