If you check Wikipedia you will find it will tell you that the Communist Party of Great Britain disbanded in 1991. Textbooks may imply that Communism is long gone and with the collapse of the Soviet Union in 1991 and China now widely regarded as a capitalist nation you would be forgiven for thinking that Communism is dead never mind the concept it exists in the UK.
However your wrong, despite officially disbanding in 1991 the Communist Party of Great Britain merely changed its name and after several mergers it appears to have re-emerged. Here is the website of CP (communist party): http://www.communist-party.org.uk/
Formed of trade unionists put off by New Labour and other Socialist supporters that have been neglected by mainstream politics, as well as long-standing communist supporters. Its not really a surprise to see a return to strength for the Communist movement, considering the growing uneven distribution of income, rising unemployment and political disillusion (voting figures can tell you this). The movement also states in its party slogan 'for peace' tapping into the growing 'anti-imperialism movement' (that being imperialism of the USA, that evil capitalist over lord). There’s also no better catalyst than Conservative Government with a regressive austerity plan at a time of stagnating growth and rising inflation.
Youth Employment is still rising and its clear to see the consequences of this, all you have to do is look at a few boarders south to find millions of revolting Arabs bringing down corrupt 'capitalist' kings. The students protests showed British students are willing flare up their own small-scale revolt and when attending an open day at Manchester University I saw plenty of Marx propaganda.
I would say main stream politicians are really not taking seriously the threats these movements pose and the media is quick to pick on plenty of far right examples (BNP EDL etc), in times of economic desperation and political disillusion people turn extreme.