If it wins an absolute majority in the second round of snap elections on Sunday, the Rassemblement National (RN) party said it would adopt an “emergency” law on immigration, but the constitution and European treaties would have to be revised for the party’s programme to be implemented.

Here AFP looks at some of the most controversial proposals of the party which is currently the most popular in France.

‘National priority’

The Rassemblement National’s top political pillar is the principle of “national preference” — now called “national priority”. It would limit welfare benefits to only French nationals.

In April, France’s Constitutional Council rejected a request by the centre-right Republicans party to hold a referendum on immigration, which would include a proposal to make access to some welfare benefits conditional on the length of residence in the country.

Disadvantaged people should not be deprived of France’s “policy of national solidarity,” said Laurent Fabius, the Socialist head of the Council. The principle of national preference was contrary to the constitution, he said.

READ MORE: What is ‘national preference’ for the French and how would it hurt foreigners?

‘Double border’

RN party leader Jordan Bardella, who will become prime minister at the age of 28 if it wins an absolute majority, has proposed the introduction of a “double border”.

The measure would tighten controls at the European Union’s external borders and impose the return of national border controls to reserve free movement within the Schengen zone to “European nationals only”, says the RN.

Yves Pascouau, a senior research associate at the Institut Jacques Delors, said that Europeans cannot be banned from entering France.

“The Schengen agreements establish freedom of movement,” he said, adding that calling a referendum or revising the constitution would not help.

“This goes beyond French matters — it’s the Schengen agreements that apply,” he said.

State medical aid

Under the RN, the AME, which guarantees free medical care to undocumented migrants who have resided in France for more than three months, would be replaced with a fund covering only life-threatening emergencies.

The 1946 constitution states that France will ensure to the individual and to the family the conditions necessary for their development and that it guarantees the protection of health for “all.”

“To completely restrict this state medical aid, or to abolish it with all the dangers for public health that this could create, is to ignore the constitutional imperative,” said Anne-Charlene Bezzina, an expert in public law.

Birthright principle

The RN wants to abolish France’s centuries-old principle of “droit du sol”, which grants French nationality to people born in France to foreign parents on certain conditions.

The far-right party says that only people born to at least one French parent should have automatic access to French nationality.

Others can make a request to obtain citizenship.

France has recently moved to revoke birthright citizenship in the French Indian Ocean territory of Mayotte to stem migration.

Bezzina suggested that the restriction of “droit du sol” across France would not pass unless the constitution was revised.

“The acquisition of nationality is enshrined in an 1889 decree, and has been continuously applied,” she said.

Dual nationals

Ahead of the first round of parliamentary elections, Bardella sparked an outcry by saying his party wanted to ban dual nationals from holding jobs in a number of sensitive sectors such as security and defence. He said “very few people” would be affected.

Macron’s government has slammed the proposal, which violates the principle of equality.

READ MORE: EXPLAINED: The French far-right’s proposal to ban dual nationals from certain jobs

“The message that you send is dual nationals are half-nationals,” Prime Minister Gabriel Attal told Bardella in a tense debate in June.

The proposal opens up the possibility of “recourse before the European Court of Human Rights or the Council of State”, said Serge Slama, an expert in public law.