A machinery exporter said fears over the future of his trade agreements prompted him to sign a letter backed by several FTSE 100 bosses campaigning for Britain to stay in the EU.

Tim Allen, managing director of Ashford-based MJ Allen Group, was among 100 business leaders to sign a letter in The Times this week which said leaving the EU would “deter investment, threaten jobs and put the economy at risk”.

His engineering business, which had a turnover of about £34 million last year, exports between a quarter and a third of its machine products to northern Europe to countries like Germany, Belgium and Sweden.

In all about 80% of its products end up being used by companies around the world, which Mr Allen said would come under threat if voters decided Britain should exit the EU on June 23.

He said: “Exporting is really important to a customer like us and our customers.

“My concern is that if the UK does leave the European Union then those trade agreements we have will get messed up.

“We could end up having to pay tariffs and duties and fill out extra paperwork, which are all things that make us less competitive.

“That could put my sales at risk and my employees at risk.”

The chief executives of Heathrow and Gatwich were among the signatories of the letter, published on Tuesday, as well as west Kents entrepreneur Jacqueline Gold, the chief executive of Ann Summers, and Sir Roger Carr, chairman of BAE Systems, which employs about 1,500 people in Rochester.

Mr Allen, who is also chairman of Kent Invicta Chamber of Commerce, said: “What I abhor as a businessman is any kind of uncertainty.

“When we are buying machinery, we are spending hundreds of thousands of pounds and for me to take a risk that all those agreements might get delayed or be in a different format in the future brings great uncertainty. It affects my confidence in being able to invest in the future.

“When we are buying machinery, we are spending hundreds of thousands of pounds and for me to take a risk that all those agreements might get delayed or be in a different format in the future brings great uncertainty..." - Tim Allen, MJ Allen Group

“While there are a lot of things wrong in the EU – I’m not a fanatic EU supporter – the status quo is most important to me and my employees.”

Will other businesses in Kent follow his position?

Mr Allen said: “I suspect if they are like me and exporting, then they will lean towards my position.

“We have UK suppliers who think they are only selling to an English company but that business might rely wholly on its ability to export.

“It is all interconnected right down to the local job.”

Several Kent MPs have declared thier position on the referendum debate.

Six MPs, including Mr Allen’s own MP Damian Green, are campaigning to remain but Canterbury’s Julian Brazier, Gravesham’s Adam Holloway and Dartford’s Gareth Johnson have all decided to campaign to leave.

Mr Johnson said: “I don’t subscribe to the view we’ll be isolated. As for trading, coming out of the EU opens up a wider market.”