Britain's government has previously urged the health sector to stockpile medical supply as drugs could be severely restricted in the event of a no-deal Brexit.
Britain's Department of Health has signed 26 non-disclosure agreements with pharmaceutical organisations preventing them from discussing their preparations ahead of a possible no-deal Brexit.
Stephen Hammond, Britain's Secretary of State for Health and Social Care, revealed the figure after a parliamentary question from Rushanara Ali, an MP from the main opposition Labour Party.
"Since July 2016, the department has signed 16 non-disclosure agreements with private companies and 10 with trade associations related to our medical supply no-deal Brexit contingency planning," Hammond said on Friday.
A Non-Disclosure Agreement (NDA) is a legal contract preventing either parties who sign it to divulge any information they share on a certain topic to a third party.
Ali condemned the practice as "utterly unacceptable."
"By effectively "gagging" these organisations, these secretive agreements are preventing essential information from being shared, are undermining transparency and are hampering businesses' ability to speak out," she added.
'Stockpiling is not the solution'
Exiting the EU without a deal on March 29, 2019 could lead to severe months-long delays at some ports which could impact the UK's supply of drugs.
The government urged the health sector to start stockpiling in August, advising they keep up to six-weeks of medical supply.
In its contingency plans released earlier this month, the Department of Health also announced that in the event of a no-deal exit from the EU it would use planes and fast-track trucks "to ensure the flow of all these products will continue unimpeded."
The government's "update on potential border delays for six months in a no deal scenario is stark," the Association of the British Pharmaceutical Industry, the largest body representing the sector in the UK, said in a statement at the time.
"Stockpiling more medicines is not the solution to this problem.
"The Government should take immediate action to open up alternative supply routes between the UK and Europe and tell companies so that they can make plans," it added.
Other services impacted
Previous parliamentary questions from November had revealed that NDAs have been used by several other governmental departments, bringing the amount of so-called gagging orders currently in force to at least 60.
The Department for Transport has 28 NDAs in force preventing companies from discussing plans about borders and customs while the the Department for Exiting the EU has six.
The latter defended itself at the time arguing they are an "entirely normal practice."