"Vote Leave" unites three groups opposed or at least dissatisfied with Britain's EU membership - Business for Britain, the Labour Leave campaign and Conservatives for Britain.

"I will vote to leave so that we can end the supremacy of EU law and the British public can take back control," UKIP's sole MP, Douglas Carswell, said in a statement.

"I want to see a campaign which brings together those from all parts of the UK who want to take back control of our countries' laws to the British Parliament," said Labour's Kate Hoey, co-chair of the "Labour Leave" campaign.

"Vote Leave" will compete with the rival "Leave.EU," which launched last month, to unlock funding to become the officially designated lobby group for an UK exit from the EU - also known as a Brexit.

"Vote Leave" announced some of its key campaign messages in a statement. Unlike "Leave.EU," which UKIP leader Nigel Farage supports, "Vote Leave" says it is not against EU membership per se. Rather, it opposes membership under current conditions.

"Technological and economic forces are changing the world fast. EU institutions cannot cope," it said. "We have lost control of vital policies. This is damaging. We need a new relationship with the European Union."

The group said it would push for a free trade deal based on "friendly cooperation" with the EU and wanted Britain to regain its independent voice at institutions like the World Trade Organization.

Meanwhile, UK Prime Minister David Cameron has long argued that the UK should remain in the EU, but that reforms must be implemented for Britain to remain in the bloc, which it joined in 1973. He has said he would campaign for Britain to remain in the EU if he is satisfied with a potential deal on his demands with Brussels.

In 2013, Cameron promised to hold an in-out referendum on EU membership, which is expected to be held either next year or in 2017.

He is likely to support an "in" campaign, which is expected to be launched in the near future.

New Labour leader Jeremy Corbyn has also been critical of the EU, but has so far been ambiguous about his stance on UK membership.

ng/msh (Reuters, AFP)