A cross-party parliamentary committee on Friday condemned the "arms race of ever more lurid claims" on both sides of Britain's European Union referendum debate, saying it was confusing the public.
Lawmakers on the Treasury committee highlighted the "highly misleading" claim by the "Vote Leave" campaign that Britain could save £350 million (460 million euros, $512 million) a week by leaving the bloc.
They also criticised the "Remain" camp for suggesting that three million jobs depended on continued membership of the EU, and that households could be up to £4,300 a year worse off in the event of a so-called Brexit.
"The arms race of ever more lurid claims and counter-claims made by both the leave and remain sides is not just confusing the public. It is impoverishing political debate," said committee chairman Andrew Tyrie, a member of the ruling Conservative party.
In a statement, he conceded that "a few grains of truth accompany the mountain of exaggeration", notably that there would be a "short-term economic cost" to a vote to leave the EU in the referendum on June 23.
In the longer-term, trade with the EU would likely fall, the committee found, but there were potential benefits in improving Britain's regulatory framework and in striking new and better trade deals.
"Vote Leave", the campaign supported by former London mayor Boris Johnson, has made the £350 million claim a central part of its bid to woo voters, splashing it across the side of its campaign bus.
It implies the money -- Britain's weekly gross contribution to the EU budget -- could be spent instead on hospitals and schools.
But it does not include the rebate worth £85 million a week, and the MPs said that even after a Brexit, the government might continue to contribute some money to the EU budget in return for access to the single market.
The committee also queried the "misleading" claim that the top 100 most "burdensome" EU regulations cost £600 million a week.
On the "Remain" side, the MPs said the three million jobs associated with EU trade should not be presented as at risk from a Brexit.
They also criticised the "tendentious" claim that a Brexit could increase the cost of imports by at least £11 billion.
"Any single number purporting to measure the impact of staying or leaving inevitably over-simplifies the complexities underlying the question on the ballot paper," Tyrie said.