Brexit could lead to price rises and delayed access to over-the-counter medicines including cough medicines and throat sweets, the drug industry has warned.

The Proprietary Association of Great Britain (PAGB) said its members, which include pharmaceutical giants GSK and Pfizer, expect to be hit with extra costs in excess of £1m as a result of leaving the EU.

PAGB, which represents the manufacturers of branded over-the-counter medicines, self-care medical devices and food supplements, said 60 percent of its members have lost faith in Theresa May’s handling of Brexit negotiations.

The body surveyed its members between 31 May and 29 June 2018 – prior to the prime minister announcing her Chequers plan.

Lib Dem health spokeswoman Judith Jolly said the survey results showed why the public should be given a vote on the final Brexit deal.

“Brexit will mean that parents will be less likely to be able to walk down to their high street chemist or supermarket and get a painkiller for their teething or feverish children. Likewise, adults will find it hard to get throat pastilles or cough medicine,” she said.

“We are always being told to use our pharmacies more, but the Conservative government has not yet convinced suppliers that they are ready to deal with their Brexit mess.”

Of the drug companies surveyed, 45 percent also said the Brexit transition period should be longer than two years – an increase of around 25 percent since the first quarter of 2018.

The government has remained firm that the UK will leave the EU at the end of March 2019.

However, ministers have hinted they would be willing to extend the planned transition period beyond December 2020.

Last month May said voters should take “comfort” from the government’s admission it is stockpiling food and medicine in case of a no-deal Brexit.