The Electoral Commission has approved The Independent Group’s application to register as a political party.
The group – made up of 11 former Labour and Tory MPs who quit their parties in February – will become Change UK.
The approval means they can put forward candidates in the European elections due to take place on 23 May – if the UK has not left the EU by then.
But the Commission rejected the party’s logo, saying it was “likely to mislead voters”.
Two Conservative MEPs, Julie Girling and Richard Ashworth, confirmed they were joining Change UK and hope to stand as candidates in the European elections.
Ms Girling said she was “fully committed to a People’s Vote on Brexit” and was “looking forward to being able to use my extensive experience as part of the Change UK team”.
The party began to form when seven Labour MPs resigned the whip due to an ongoing row about the leadership’s handling of anti-Semitism, and its position on Brexit.
Two days later, another Labour MP, Joan Ryan, joined the ranks, followed by three Conservative backbenchers, who criticised the government for letting the “hard-line anti-EU awkward squad” take over their party.
Since then, the group has been a vocal supporter of the “People’s Vote” campaign, calling for another referendum on Brexit.
The 11 MPs sat as a grouping in Parliament called “The Independent Group”, but applied to become a party at the end of March in case European elections went ahead.