The Democratic Alliance for the Betterment and Progress of Hong Kong said it has found that hundreds of thousands of people are waiting to get new permits as many have expired during the three years when the border was closed off, she said.

Lee said she has told Hong Kong and Macao Affairs Office director Xia Baolong about the issue in a meeting on Friday.

"My suggestion is that central and the SAR authorities could adopt special arrangements by extending home return permits for six months, so that citizens and students could return home in the mainland and attend exchange activities," she said.

Lee said she proposed the requirement for travelers to make health declarations when crossing the border be scrapped during the meeting.

The authorities should assist Hongkongers who do not have e-payment tools and have difficulties when making payments in the mainland, she said.

A Hongkonger, whose home-return permit expires on August 1, said she has been trying to make an appointment for the renewal on the website of China Travel Service a travel agent that issues permits and visas to the mainland - for two weeks now.

"Unfortunately, I haven't been able to secure a booking despite my daily attempts," she said.

"The first thing I do, after I wake up every morning, is to check the site for bookings for the next 121 days. But it's always already full they don't do walk-in services 'unless for special circumstances.'"

She said it would be good if the permit validity can be extended for six months so that people can have enough time to register.

Allen, who recently became a Hong Kong permanent citizen, said he has to wait for three months to apply for the permit, as he tried to make an appointment last month but found all slots were fully booked until mid-June.

China Travel Service should handle' applications faster, he said.

"China Travel Service is earning a lot as a middleman to help Hongkongers apply for the home-return permits and they should work harder," Allen said. "But I don't have confidence in the company."

DAB Legislative Council member Kwok Lai-ling called for authorities to issue single-use permits for students who are studying the citizenship and social development subject and need to go to the mainland on exchange visits.

Secretary for Education Christine Choi Yuk-lin said China Travel Service has been working overtime for days to handle students' applications.

Choi said the government is analyzing the requirement for school principals to attend programs in the mainland as well.