Lawmakers Gary Zhang and Yang Wing-kit on Thursday called on the government to set up a ballot system for cross-border travellers rather than any quotas on a first-come, first-served basis, if there are to be restrictions on numbers when quarantine-free journeys are allowed again.

SAR officials say they plan to allow quarantine-free travel from Sunday but are yet to announce any details.

A source earlier told RTHK that an initial quota of 50,000 people travelling in each direction would be adopted at first.

But Zhang said such a cap would be too low.

"The first-come, first served model would bring about many problems, because a large number of citizens would rush to the websites to compete for places," he said on RTHK's Hong Kong Today programme.

"This would definitely give scalpers an opportunity to take advantage of [the situation]."

Yang made the same point, saying on another RTHK programme that there should be a ballot system instead of quotas on a first-come, first served basis.

However, he also said he thinks the expected 50,000 places per day would be enough, noting that recently, around 30,000 people took part in daily draws for quarantine hotels in Shenzhen.

Meanwhile, the chairman of the Hong Kong Seamen's Union, Cheung Sai-teng, said that only five ferries may be put into operation for services to Macau at first, compared to the more than 30 running before the pandemic.

He said it takes time to recruit frontline staff and some ferries require maintenance work.