Security minister Dan Jarvis told parliament that Russia would be subject to the most stringent restrictions of the Foreign Influence Registration Scheme (Firs).

It becomes the second country after Iran to be added to the so-called enhanced tier of the scheme, which aims to boost the UK's national security against covert foreign influences.

It means anyone directed by the Russian government -- or by an entity linked to it -- to carry out activities in the UK must declare the work or face five years in prison.

"Russia presents an acute threat to UK national security," said Jarvis, a junior minister in the interior ministry known as the Home Office.

He highlighted "hostile acts" such as the use of a deadly nerve agent in Salisbury, southern England in 2018, espionage, arson and cyber attacks, including the targeting of UK parliamentarians through spear-phishing campaigns.

Jarvis also cited Russia's invasion of Ukraine and its "intent to undermine European and global security".

The Home Office said anyone working for Russian government agencies, armed forces, intelligence services and police force, parliaments and their judiciaries would be subject to the measures.

Jarvis added the government also intends to "specify several political parties which are controlled by Russia, including the United Russia party" under the scheme.

- China call -

Home Secretary Yvette Cooper said the rules "will make it harder for Russia to conduct hostile acts against us in future".

Firs had been due to go into effect in 2024 but the new Labour government of Prime Minister Keir Starmer announced shortly after elections in July that it was being delayed.

Jarvis announced it would now take effect from July 1.

Under Firs' lower tier, anyone seeking to influence political decisions on behalf of any foreign power must register their activities.

The enhanced tier is a status reserved for nations that are deemed to pose a risk to the safety of UK national interests.

It requires all activities carried out at the instruction of any designated state to be registered.

Last month, the government announced that Iran would be in the higher tier, meaning anyone working for its regime, including intelligence services and the Revolutionary Guard, must declare their work.

The government has so far resisted calls to add China to the top tier, as it seeks to improve relations with Beijing in the hope it will spur Chinese investment in Britain's economy.

Conservative MP Iain Duncan Smith, a known China hawk, said the Asian giant should be included because it was "at the epicentre of everything to disrupt democracy and freedom".

Jarvis said he would not speculate on "which countries may or may not specified in the future".