The Centre for Cities, a high profile economic think tank, made the claim in a paper which analyses how Britain's cities – a criteria in which it includes Telford – trade with the rest of the world.
The report concludes that of all the towns and cities analysed, Telford has the highest proportion of exports that go to the EU, leaving it most at risk from the introduction of extra costs on exporting.
It states: "Telford’s exports were the most dependent on the EU, with 70 per cent of all of its exports going to EU countries. It was followed by York and Wakefield."
The report also concluded that a Brexit agreement that does not preserve frictionless access to the European Union for service industries would risk a sharp fall in trade, putting jobs at risk.
Richard Sheehan, chief executive of Shropshire Chamber of Commerce, said that the county's businesses have been successful in trading with EU markets, and across the world, but that certainty is needed over the future position.
He called on the government to make sure that any deal does not hinder businesses in accessing markets.
He said: "We know that a significant amount of exports go on from Shropshire to the EU as a whole. As a processor of export documentation and provider of export support through the DIT (Department for International Trade) contract we are working with companies across the county to encourage them to access many overseas markets to support the growth of their businesses.
"Clearly the introduction of tariffs and any slowing down of the import/export procedures will impact on the very good work going on in the Shropshire business community at the moment.
"Particularly where we as a chamber have been campaigning hard to avoid a no-deal scenario.
"We are still receiving many enquiries, almost on a daily basis, wanting to know what paperwork and processes will need to be in place for orders they are looking to take but deliver in the future and that is proving a challenge for anyone to support because clearly the detail is no there at this current time.
"Where I think the studies are vitally important, and I am sure it is very creditable in terms of the intelligence it provides, what we are focussing on is encouraging government to come up with a very smooth transition and ensure that businesses are not hindered in any way as they attempt to access these very important and substantial markets."