British businesses faces a tough choice in this year's general election, the CEO of the world's biggest advertising agency told CNBC Monday.
Voters go the polls on May 7 in an election that many analysts say is too close to call.
"It's a very difficult choice at the election if you're in business," said Martin Sorrell, the CEO of WPP Group.
He said businesses were faced with the choice of a government led by the Conservatives, who lead the current coalition and promise a referendum on Britain's membership of the European Union, and the opposition Labour Party.
"I doubt the Conservatives will be the majority party, but they may be in control of a coalition and you're faced with the uncertainty of an EU referendum. It's either a neutral or negative impact, it's not positive," Sorrell said.
"If you vote Labour, the Labour platform seems to be bashing business, which makes business people a little bit uncomfortable," he added.