As expected, a host of business heavyweights have come out in favor of Britain staying in Europe, Business Insider says.

In a letter published in Times, on Tuesday, Feb 23, almost 200 business leaders call for Brits to vote to stay in the European Union in the upcoming referendum on membership.

The signatories include executives at giants such as BP, Credit Suisse, BT, Vodafone, HSBC, Asda, Marks & Spencer, Airbus, AstraZeneca, BAE Systems, and Ryanair.

The key paragraph in the letter signed by 198 business people — including 36 FTSE 100 bosses — reads: “Business needs unrestricted access to the European market of 500 million people in order to continue to grow, invest, and create jobs. We believe that leaving the EU would deter investment, threaten jobs, and put the economy at risk. Britain will be stronger, safer, and better off remaining a member of the EU.”

The signatories employ hundreds of thousands of people across a wide range of industries in the UK, according to the letter, which was published in The Times.

In a separate letter also published in today's Times, Trade Union Council leader Frances O'Grady calls for Britain to remain within the EU, writing:

If the Brexit camp get their way many vital workplace benefits that the EU has given us — paid holidays, extra maternity rights, and better conditions for part-time workers — could be for the chop. That may prove attractive to unenlightened business leaders but it will not win the hearts and minds of working people buckling under the strain of insecurity and reduced living standards.

Prime Minister David Cameron announced over the weekend that the pre-announced referendum on Britain's membership would be held on June 23. The date was named after Cameron secured what he saw as a decisive deal with Europe on reforming Britain's membership of the 25 country bloc.

But the Prime Minister, himself pro-European, has suffered several setbacks since announcing the date. Six Tory cabinet members, including Justice Secretary Michael Gove, have come out in favor of a so-called "Brexit" — a British exit from Europe — while Mayor of London Boris Johnson has also declared that Britain should leave.