This is what the Institute for Fiscal Studies has to say about the so-called "brexit bonus" trumpeted by the right wing tabloids - the fact is we will have less to spend on the NHS than we would if we reamained in the EU.
"In other words, so far the implication is that Brexit has reduced rather than increased the funds available for the NHS (and other public services), both in the short and long term. Although subsequent growth after the OBR’s forecast has been slightly stronger than expected, the medium-term outlook is now gloomier than in November 2016.
All forecasts are uncertain, and the fact we do not yet know what the UK’s post-Brexit relationship with the EU will be adds additional uncertainty. However, the OBR forecast is predicated on a relatively smooth transition, putting it at the optimistic end of the spectrum; in a ‘no deal’ scenario, in which the UK reverted to World Trade Organisation (WTO) rules, the economic dislocation would be much larger. Moreover, the OBR has not as yet incorporated any longer-term negative impacts of Brexit on productivity, and some economists expect these to be significant. "
www.ifs.org.uk/publications/10354