LONDON (Reuters) - Britain expects to have removed Chinese-made surveillance technology from sensitive sites by April 2025, as it seeks to tighten security amid increasing concerns about Beijing's spying activities, the British government said on Monday.

Anxiety has mounted across Europe about China's alleged espionage activity. British police last week charged two men with spying for China, including one reported to have worked as a researcher in Britain's parliament for a prominent lawmaker.

In November 2022, the British government said that visual surveillance systems produced by companies subject to China's National Intelligence Law should not be used at sensitive sites such as government buildings and military bases.

Lawmakers have also called for a ban on the sale and use of security cameras made by Hikvision and Dahua, two partly state-owned Chinese firms, over privacy fears.

The government said it had found that the vast majority of sensitive sites had never deployed the equipment. Of the small number of sites that did have it, about 50% had since replaced it, and progress was being made for removal of the rest.

"Work is pressing ahead to remove remaining devices, with approximately 70% of sites expected to have their surveillance equipment removed by October this year, and all remaining sites on track for complete replacement no later than April 2025," junior minister Alex Burghart said in the statement.

Britain warned six months ago that Chinese spies were targeting British officials in sensitive positions in politics, defence and business as part of an increasingly sophisticated spying operation to gain access to secrets.

"The government takes the security of the UK's citizens, systems and establishments extremely seriously and we have a range of measures in place to scrutinise the integrity of our arrangements," the statement added.

(Reporting by Sarah Young; editing by Michael Holden)