A delegation from Hong Kong has been invited by the British government to attend a flagship arms fair in London despite a promise made by the former foreign secretary in June to halt exports of teargas to the crisis-hit territory.

The surprise invitation to the DSEI show, which showcases security and military products, was confirmed by the Department for International Trade now run by Liz Truss.

Officials tried to downplay the significance of the invite, arguing that it did not imply there would be any future arms sales to Hong Kong, but campaigners questioned whether the territory should be allowed to attend given the crisis on the streets in the former British colony.

Andrew Smith, a spokesman for the Campaign Against the Arms Trade, said: “The Hong Kong police are using UK-made arms against campaigners right now. It is a disgrace that they have been invited to buy even more.”

Hong Kong is in the midst of its worst political crisis since the British handover of the territory to China in 1997. During the protests, which began in opposition to a now suspended extradition law, almost 2,000 rounds of teargas have been fired.

Canisters recovered by protesters show that some of the CS gas used had been manufactured by a British company, Chemring, at a factory in Derby, which partly prompted Jeremy Hunt to announce the export ban. Britain had licensed £9.4m of arms sales and security equipment to Hong Kong since 2014.

The then foreign secretary, who was sacked last month by the prime minister, Boris Johnson, had declared that no export licences to Hong Kong would be approved until concerns about human rights abuses were “thoroughly addressed”.

But the list published by the DIT of delegations invited on 23 July – Hunt’s last full day as foreign secretary – names Hong Kong, as well as eight countries identified by the Foreign Office as a “priority country” in its latest annual review of human rights and democracy.

They include Saudi Arabia, where a failure by British ministers to consider the impact of civilian casualties in Yemen from bombing by the country’s air force has led to the court of appeal declaring that UK exports had been conducted unlawfully until a proper assessment is carried out.

Another is Bahrain. This week two staff from the Gulf state’s embassy in London were accused of assaulting an activist who climbed to the roof of the five-storey building in Belgravia, in protest against the pending execution of two men. The embassy has denied the claim.

The remaining six human rights priority countries invited by the DIT to the DSEI are Bangladesh, Colombia, Egypt, Israel, Pakistan and Uzbekistan.

Lloyd Russell-Moyle, a Labour MP, said: “The government’s approved attendees are eerily similar to its official list of human rights abusers ... I presume this is what Johnson means by global Britain.”

The size and importance of the national delegations vary, but some are substantial and include senior figures able to make purchasing decisions. Over 1,600 exhibitors are expected to be present at the event at London’s Excel centre, which will also feature 40 “international pavilions”.

The Department for International Trade said: “The invitation does not imply that any future export licences would be granted to Hong Kong.”