“Welcome to Steve Bannon who will address the FN ... at our congress and will meet ML [Le Pen]. The people are waking up and taking their destiny in hand,” he wrote.

Soon afterwards Aliot tweeted a photograph of him shaking hands with Bannon, who he wrote “represents rejection of the establishment of which one of the worst symbols is the EU in Brussels. He has understood like Trump and Matteo Salvini [the head of the Italian League] the wish of the people to control their own destiny.”

Ten months ago, the party was on a high after Le Pen saw off the Socialist candidate to take the FN into the second round of the presidential election with unprecedented support, though not enough to defeat Macron. However, this weekend’s conference to transform and “refound” the party is threatening to fall short of its goals of unity and optimism.

Bruno Cautrès, of the centre for political research at Sciences Po, said the party was undergoing a “crisis of Marine Le Pen’s leadership”.

“Voters and even party members are questioning her ability, or not, to continue the feeling that the adventure continues and the party can still go forward,” Cautrès told 20 Minutes news programme.

A recent opinion poll by Kantar Sofres confirmed the diagnosis: 55 per cent of respondents said they did not wish Le Pen to be the FN candidate at the next presidential election, and less than one in five believed she inspired confidence.

At the conference in Lille, in the FN’s northern heartlands, Le Pen will urge the party to move away from the mindset of being a permanent opposition, ground it has occupied since it was founded, to broadening its appeal with a view to governing.

Since taking over in 2011 with her father’s blessing, Le Pen has embarked on a process of “de-demonising” the FN, which has involved shrugging off its xenophobic, bully-boy image.

In the presidential election, it appeared this strategy paid off, as Le Pen gained more than 10 million votes (33.9 per cent) in the final round, despite her bizarre and catastrophic performance in a debate with Macron, which cost her support.

A questionnaire sent to party members found immigration remains the biggest preoccupation of FN supporters.

The responses to the pre-conference survey are likely to echo warnings from Florian Philippot, Le Pen’s closest aide and strategist until he quit the FN last year, that it risked an “absolutely terrifying” return to its dark past, which he claimed was alienating voters.

While Le Pen is facing no immediate threat of overthrow – she is expected to be re-elected unopposed as party president – her father, Jean-Marie, who was thrown out of the FN for racist remarks, continues to snipe from the sidelines.

Last month, a court of appeal confirmed his exclusion as honorary president of the FN, a position the conference is expected to vote to drop.

Le Pen’s young and ambitious niece Marion Maréchal-Le Pen, who claims to have withdrawn temporarily from politics, is also biding her time.

The FN leader told Europe 1 radio that party members had been asked 80 questions on major policy issues, including Europe, immigration, employment and the environment.

“There may be surprises for some when they read the answers,” she said.

Party members supported legalised euthanasia, which Le Pen opposes, favour of gay marriage and are against the death penalty, she said.

“The questionnaire shows we need to be more nuanced on certain subjects,” Le Pen said. “It validates the party line of neither right nor left.”

Le Pen told French television on Friday that a name change was needed to show the FN had grown up and become “adult”.

“Right or left doesn’t mean anything and doesn’t reflect the real division in France today which is between those who feel the nation is an obstacle and those who feel the nation is a jewel to be defended,” she said. Le Pen said the FN had two central aims: “to defend the identity, culture and security of the French involving the fight against immigration” and defending “France’s social model and sovereignty”.