LONDON (AFP) - British MPs urged the government to take a tougher line with China in an emergency House of Commons debate on Tuesday after a group of them was refused visas to visit Hong Kong.

Members of the Foreign Affairs Committee were declined visas to visit Hong Kong later this month by Chinese authorities who accused the former colonial power of seeking to interfere in pro-democracy protests.

While Prime Minister David Cameron's government says the situation can be smoothed over with talks, it has caused outrage among lawmakers who want ministers to take a firmer stance.

The refusal complicates British efforts to reset relations with China that were plunged into difficulties after Cameron met the Dalai Lama at Downing Street in 2012.

During the rare debate, Hugo Swire, a Foreign Office minister, called China's ban "wholly unjustified" but stressed the need to "pursue dialogue in issues even when we disagree".

"We have an indispensable relationship with China," he told the Commons. "It's important that this relationship is based on mutual understanding and respect."

Cameron's official spokesman also downplayed fears that the ban could affect trade between Britain and China. British exports to China were worth an average £1 billion (S$2.05 billion) a month in 2013.

"Where we have differences... we discuss those types of issues alongside and as part of the full range of bilateral relations," he said.

But members of the committee speaking in the debate said the government was not going far enough.

Andrew Rosindell, a member of Cameron's Conservative party, urged that the Chinese ambassador be summoned to the Foreign Office to explain what had happened.

He described the visa ban as "shameful" and "nothing short of an outrage".

"Britain has to decide whether we tolerate and simply accept China's behaviour... or whether we're prepared to reconsider" the nature of the relationship, Rosindell added.

Another Conservative, John Stanley, said he was "very disappointed" that the British foreign ministry had not made a stronger protest, while senior Labour lawmaker Keith Vaz insisted on the need for a "very clear response" from the ministry.

Mass pro-democracy demonstrations have been taking place in Hong Kong since September.

The original founders of the Occupy movement said Tuesday they were set to "surrender" but it is thought unlikely that the students who make up the bulk of the protestors will listen to their call for a retreat.