|The UK government was warned that thousands of malicious emails were hitting its networks each month [EPA]
"Terrorism" and cyber attacks are to be identified as the main threats to Britain as the government unveils a new security strategy.
The plan, which is being revealed later on Monday, is expected to be used to justify spending cuts under the coalition government's austerity measures.
Cyber terrorism will be identified as one of the so-called "tier one" threats facing the UK, a week after the government's eavesdropping agency warned of serious and repeated attacks, with 20,000 malicious emails sent to government networks each month.
Theresa May, Britain's home secretary, said cyber security "is a growing threat".
"It's a threat to government, it's a threat to business and indeed to personal security. We've identified this as a new and growing threat to the UK," she told the BBC.
The new strategy would be unveiled days before David Cameron, the prime minister, is expected to announce defence spending cuts, which could see a major reduction in troops, tanks and artillery pieces.
National spending cuts will be announced on Wednesday where government ministries are likely to see their budgets reduced by up to 25 per cent over four years - the harshest austerity measures the country has seen since World War II.
However, funding to battle "terrorism" and cyber attacks is expected to rise, according to two government officials who spoke on condition of anonymity.
A parliamentary watchdog has already criticised Monday's report, saying that given the size of expected spending cuts, it doubted "whether the government has the capacity to deliver a (review) which is any way strategic".
Last week, Hillary Clinton, the US secretary of state, said she was "worried" that defence cuts might limit Nato's effectiveness in Afghanistan, and Robert Gates, the US defence secretary, voiced concern that Washington would have to make up any shortfall in capacity.
The Conservative Party, which heads the ruling coalition, is traditionally seen as pro-military, and arguments over defence cuts have exposed rifts within its ranks.