France’s government presented a bill Wednesday to toughen immigration and asylum laws by doubling the time migrants can be detained, strengthening police powers to search them, and shortening the time migrants have to appeal rejected asylum claims.

The proposed measures have angered some lawmakers from President Emmanuel Macron’s centrist République en Marche group in the National Assembly, which until now has unflinchingly backed the president’s policies. Some members say they could abstain from voting for the bill if it isn’t softened.

“The bill seems too restrictive on some points, or it constitutes a revocation of freedoms,” Martine Wonner, one of the lawmakers critical of Mr. Macron’s plans, said in an interview with French paper 20 Minutes.

Presenting the bill Wednesday, the government said the changes to immigration and asylum laws were in line with Mr. Macron’s election promises. Along with allowing migrants to be detained for up to 90 days and giving police greater powers to fingerprint them, the bill also foresees simplifying and speeding up processes for asylum demands, and expanding programs to welcome foreign students, researchers and entrepreneurs. Interior minister Gérard Collomb said the new law would also increase language training and help accepted asylum seekers find work.

Lawmakers’ resistance to the immigration and asylum bill represents the first public signs of dissension within the large majority Mr. Macron won in June’s legislative elections.

That majority—founded on Mr. Macron’s call to overcome the left-right divide of traditional policies—has approved a host of contentious measures, from slashing wealth taxes to loosening France’s labor laws.

Mr. Collomb said he expected few lawmakers would ultimately vote against the new proposals.

“I’ve no concerns about the majority,” he said. “I think everyone will realize we have a balanced bill.”

The interior minister also defended the more punitive aspects of the bill, saying France faces a surge in migrants fleeing economic difficulties and conflicts in Syria and sub-Saharan Africa. In 2017, 100,000 people requested asylum in France—a 17% increase from 2016—and another 85,000 were turned away at the country’s borders.

But some lawmakers said they remain concerned the bill is too tough. A small group of lawmakers plans to present amendments to challenge the government.

“The parliamentary work, which is only just beginning, will allow us to continue re-balancing the bill,” said Matthieu Orphelin, a lawmaker in Mr. Macron’s majority.