A visiting member of the British House of Lords has urged London to remember its obligations to its former colony Hong Kong, even as it pursues post-Brexit trade deals with Beijing.

Lord Paddy Ashdown, a former leader of the Liberal Democrats in the UK, is wrapping up a two-day fact-finding mission to the territory.

Speaking to the Foreign Correspondents’ Club today, Lord Ashdown said Britain must continue to do all it can to ensure that Beijing lives up to its obligations to uphold human rights and freedoms in Hong Kong agreed under the Sino-British Joint Declaration in 1984.

He noted that the then-British prime minister John Major had undertaken to pursue every means of redress if there’s even a suggestion of any breach.

"This is not a promise that can be lightly laid aside because it proves inconvenient to a British government obsessed with finding trade deals because it wishes to be outside Europe. As [former Hong Kong governor] Chris Patten has said, Britain risks selling its honor here,'' Ashdown said.

He added that it is in Beijing’s interest to demonstrate that it is living up to its obligations under the Joint Declaration.

"One Country, Two Systems is the slogan under which Beijing may want to draw others back to the fold,” he said. "Honoring scrupulously the Anglo-Chinese deal in both letter and spirit will enhance that possibility. Any perceived failure to do so will weaken it.”

Lord Ashdown suggested that while Hong Kong still enjoys an independent judiciary, some of Beijing’s actions – such as the alleged kidnap of Causeway Bay bookseller Lee Bo – is cause for concern.

"The abduction of Hong Kong booksellers into the mainland simply for having published books critical of China's leaders undermines confidence both in the rule of law and in the principle of free speech,” he said.

Lord Ashdown also questioned the wisdom of prosecuting prominent student leaders Nathan Law, Joshua Wong Chi-fung and Alex Chow over a protest that sparked the 2014 Occupy Movement.

"Of course it is the case that those who break the law should be judged. But… whether it is wise for the full might and majesty of a global superpower to come down on three young enthusiastic student demonstrators -- one of whom is a directly elected legislator -- who may have over stepped the limits is I think, a different matter.”

They were sentenced to between six and eight months in prison in August, but are currently free on bail as they apply to take the case to Hong Kong's top court.-RTHK