China criticised Boris Johnson's "incorrect" stance after he called for Hong Kong to make more progress towards democracy ahead of the 20th anniversary of the former British colony's return to Chinese authority.

The Foreign Secretary sparked anger in Beijing after saying it was crucial for Hong Kong to retain a "high degree of autonomy and rule of law" in a statement to mark the handover of power from the UK to China on 1 July 1997.

Mr Johnson made no direct criticism of China's communist regime, but called on all Hong Kong parties to "progress towards a more democratic and accountable system of government" on Thursday.

Hong Kong activists preserve the past Show all 22 1 /22 Hong Kong activists preserve the past Hong Kong activists preserve the past HK URBEX members, inspect the interior of an abandoned British army barracks in Hong Kong Reuters Hong Kong activists preserve the past HK URBEX members are seen through a hole in the fence at an abandoned British army barracks in Hong Kong, China, June 1, 2017 Reuters Hong Kong activists preserve the past An abandoned British army barracks is seen through thick fog in Hong Kong, China, June 1, 2017 Reuters Hong Kong activists preserve the past A HK URBEX member, stands at an abandoned British army barracks in Hong Kong, China, June 1, 2017 Reuters Hong Kong activists preserve the past A HK URBEX member looks through a window at an abandoned British army barracks in Hong Kong, China, June 1, 2017 Reuters Hong Kong activists preserve the past A HK URBEX member walks through an abandoned British army barracks in Hong Kong, China, June 1, 2017 Reuters Hong Kong activists preserve the past A HK URBEX member looks around an abandoned residential building in Hong Kong, China, June 7, 2017 Reuters Hong Kong activists preserve the past HK URBEX members walk towards an abandoned British army barracks in Hong Kong, China, June 1, 2017 Reuters Hong Kong activists preserve the past A HK URBEX member climbs a ladder at an abandoned British army barracks in Hong Kong, China, June 1, 2017 Reuters Hong Kong activists preserve the past A HK URBEX member inspects the interior of an abandoned British army barracks in Hong Kong, China, June 1, 2017 Reuters Hong Kong activists preserve the past A HK URBEX member, looks at a newspaper from 1982, inside an abandoned residential building in Hong Kong, China, June 7, 2017 Reuters Hong Kong activists preserve the past A tag is seen inside an abandoned British army barracks in Hong Kong, China, June 1, 2017 Reuters Hong Kong activists preserve the past An external view of an abandoned mansion called Yu Yuen, built the 1920's colonial era, is seen in Hong Kong, China, June 7, 2017 Reuters Hong Kong activists preserve the past HK URBEX members look around an abandoned residential building in Hong Kong, China, June 7, 2017 Reuters Hong Kong activists preserve the past A soft toy is seen inside an abandoned residential building in Hong Kong, China, June 7, 2017 Reuters Hong Kong activists preserve the past An interior view of an abandoned mansion called Yu Yuen, built during the colonial era of the 1920's, in Hong Kong, China, June 7, 2017 Reuters Hong Kong activists preserve the past An interior view of an abandoned mansion called Yu Yuen, built during the colonial era in the 1920's, is seen in Hong Kong, China, June 7, 2017 Reuters Hong Kong activists preserve the past People walk past the abandoned historic Central Market, which was built in the 1930's during the colonial era, in Hong Kong, China, June 10, 2017 Reuters Hong Kong activists preserve the past HK URBEX members inspect an abandoned residential building in Hong Kong, China, June 7, 2017 Reuters Hong Kong activists preserve the past An external view of the now closed Wing Woo Grocery Shop on Wellington Street, which was built during the colonial era in the 1870's, in Hong Kong, China, June 10, 2017 Reuters Hong Kong activists preserve the past Colonial era buildings (front to back), St John's Cathedral, former Central Government Offices and Government House are seen in Hong Kong, China, June 3, 2017 Reuters Hong Kong activists preserve the past A man stands outside the abandoned historic Central Market, which was built in the 1930's during the colonial era in Hong Kong, China, June 10, 2017 Reuters

Chinese officials responded to the statement by chastising the Conservative front bencher for speaking about their "internal affairs".

"Hong Kong is a special administrative region of China, and therefore Hong Kong affairs are China’s internal affairs," said foreign ministry spokesman Lu Kang.

Mr Lu made clear he was responding to Mr Johnson's statement and said "outsiders should not make incorrect remarks" about China's policies towards Hong Kong, according China's state news agency Xinhua.

The minister also claimed that the 1984 Sino-British joint declaration, which guaranteed that Hong Kong's capitalist system would remain unchanged for 50 years, doesn't have any "binding force" - a comment sure to worry pro democracy activists in the region.

Mr Lu insisted that the treaty "no longer has any practical significance", despite it being the key agreement which paved the way for Britain to transfer sovereignty to China.

The British foreign office quickly issued a reply, telling Reuters: "The Sino-British joint declaration remains as valid today as it did when it was signed over 30 years ago.

“It is a legally binding treaty, registered with the UN and continues to be in force. As a co-signatory, the UK government is committed to monitoring its implementation closely.”

Democracy activists in Hong Kong have criticised the British government for not defending their rights against the Chinese government, according to the Guardian.

In 2015 five Hong Kong booksellers were kidnapped by Chinese agents for peddling works making salacious claims about top Communist Party officials.

Hong Kong's last governor, Chris Patten, told the Guardian the UK had been "kowtowing" to Beijing over human rights issues, adding: “Unless you bow low enough you will never do any business in China."

Mr Johnson said in his statement that the UK exports more than £8bn worth of goods and services to Hong Kong every year, making it Britain's second biggest export market in Asia.

Liu Xiaoming, Beijing's ambassador to London, suggested that Britain's relationship with China could face difficulties if the UK challenges the Communist party over Hong Kong.

Mr Liu told Xinhua: “I hope that all sectors in Britain will respect the fact that Hong Kong has returned to China.

“Hong Kong-related issues must be handled properly. I hope that by recognising and respecting the above we will continue to make Hong Kong a positive factor in China-UK relations.