The UK pharmaceuticals sector has been told to prepare for a “crisis” Brexit scenario of drastically reduced access to European markets and hundreds of millions of pounds of restructuring costs unless a swift regulatory deal can be struck with Brussels.

Trade body the Association of the British Pharmaceutical Industry (ABPI), which lobbies for the 60,000-strong sector, told The Telegraph new regulatory guidance published by the European Medicines Agency (EMA) this week posed a risk to UK pharma jobs and to public health on both sides of the Channel.

The EMA - one of two highly-prized EU regulatory bodies currently based in the UK that is expected to move to the Continent - issued a paper detailing how firms should prepare for Brexit.

In it the regulator advised UK-based pharma companies to move hundreds of roles and functions to an EU member state ahead of Brexit in order to maintain their existing rights to sell medicines in the common market.

Among the demands are that EMA-approved medicine batching facilities and 153 UK-based EMA-approved experts that monitor the safety of European drugs move to an EU member state.

The paper also warned that as things stand the UK faces a sharp hike in regulation and stringent checks on medicine exports from March 30, 2019, in terms of finished products when they arrive in the European common market.