The Liberal Party on Monday proposed introducing a "departure tax" on permanent residents travelling out of Hong Kong by land, air or sea as a way of boosting government revenue amid a deficit.

It's one of a series of recommendations made by the party at a meeting with Financial Secretary Paul Chan to discuss the upcoming budget.

Party leader Tommy Cheung said the departure tax could be used as a temporary measure to deal with the current financial challenges.

"This is only going to be a temporary measure until the deficit turns around, and once it does we think the government should abandon it... It's not a lot of money, but we're thinking about different revenues," he said.

Other measures they proposed include more child allowances for taxpayers and the creation of a mega-events fund to boost tourism.

They also hope that Beijing could relax visa rules for visitors from Shenzhen so that they can make multiple trips to the SAR every week, and increase the number of mainland cities covered by the Individual Visit Scheme.