Richard Corbett says he wants the chance to rebut anti-EU claims Mr Sykes is bankrolling in an advertising campaign which starts today.
The campaign will target every household on a platform of regaining national sovereignty in key areas where powers have been pooled with the rest of the EU, and scrapping EU farming and fisheries policies.
Mr Sykes, one of five financial backers of the campaign – the other four have not been named – is a former financial supporter of the UK Independence Party, having quit the Conservative Party over its EU policy in 2001.
Now he is back in the spotlight battling to reverse EU integration at a time when public disillusion with the Union is on the rise.
The speakout campaign will be "an outbreak of truth", according to Mr Sykes.
But Mr Corbett claims the property developer has his facts wrong on the UK and the EU and wants the chance to take him on in public.
"With the amount of money Mr Sykes has thrown at this project I would have expected him to have spent at least some of his budget on research in order to enable him to present his argument factually," said Mr Corbett.
"However, the advert I have seen is riddled with inaccuracies and errors and is largely typical Eurosceptic conjecture.
"I hardly see how this amounts to an outbreak of truth."
Mr Corbett was referring to a speakout advert stating that more than half of the UK's laws – and 80 per cent of them according to some – originate behind closed doors in Brussels.
The MEP said that the House of Commons library puts the amount of UK laws originating from the EU at just nine per cent.
And he pointed out that laws from Brussels are adopted by ministers representing the national elected governments of the member states and elected MEPs from the 25 countries.
However, Mr Corbett agrees with Mr Sykes that the subject needs more airing: "The issue of Europe does deserve greater prominence in the UK but it is important that the public is informed fairly and correctly and not with myth and nonsense.
"This is why I have challenged Mr Sykes to take part in a debate with me on the UK's relationship with the EU.
"The public deserve to be presented with both sides of the discussion and left to make up their own minds rather than being sent biased propaganda which gives pro-Europeans no opportunity for recourse."
A campaign spokesman said: "We welcome Mr Corbett's challenge and will be in touch with him shortly. We agree with him that there is a desperate need for a debate on this topic.
"Our own opinion polling, carried out by YouGov over the last week shows that a staggering 95 per cent of people say they have had very little or no information from their MP or MEP about our relationship with the European Union.
"Just one per cent of the people say they have had a lot of information."
william.green@ypn.co.uk

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