Mariani, 60, had been hinting for weeks that he was planning to leave but said he agreed to join the RN after Le Pen dropped a demand for France to quit the European Union.
Mariani, along with a former MP with UMP (the predecessor of the LR), Jean-Paul Garraud, are now on the RN’s ticket for European parliament elections in May.
The mainstream right has tried to minimise Mariani’s defection by calling him a marginal member of the party.
Drifting to the right
Mariani, who was an MP for 22 years and served as transport minister from 2010-2012, had been drifting to the right of the mainstream. He helped create an informal parliamentary group in June 2010, called the Popular Right, supporting some of the more right-wing aspects of Sarkozy’s platform.
During the 2012 legislative elections, the group lost more than half of its members who were not re-elected, including Mariani.
The decision to leave LR appears to be strategic. Mariani has hailed Le Pen as the only viable choice to beat Emmanuel Macron’s party, which swept the 2017 French parliamentary elections.
Macron’s party won partly by taking votes away from the mainstream right. The LR leader, Laurent Wauquiez, has since moved the party towards far right ideas, particularly on immigration and security issues.
That shift has alienated the more moderate LR members, like Alain Juppé, a former prime minister, who did not renew his party membership last week, saying that Macron was moving in the right direction.
Looking ahead to EU elections
"I do not agree with some points on French economic policy, but that’s not the issue,” Mariani said on Wednesday.
On Monday, the RN anointed 23-year old Jordan Bardella as the head of its list for the European elections. It says it will unveil on Sunday its other main candidates for the polls. Opinion surveys put the party ahead of LR in voting intentions, in an election that will be presented as a referendum on Macron.