Don't be fooled by the rise of these small parties with their simplistic solutions

The Prime Minister's tame defensiveness has left large amounts of political space on the centre-left of politics

Nervy Labour and Conservative strategists are becoming increasingly alarmed by the rise of smaller political parties. They are almost more worried about this than they are about each other. After all they are used to fighting each other. The relatively strong showing of the United Kingdom Independence Party, the British National Party, the Greens and the anti-war Respect forces the bigger parties on to new terrain. They are not entirely sure what to do about it or what the longer-term electoral consequences will be.

Nervy Labour and Conservative strategists are becoming increasingly alarmed by the rise of smaller political parties. They are almost more worried about this than they are about each other. After all they are used to fighting each other. The relatively strong showing of the United Kingdom Independence Party, the British National Party, the Greens and the anti-war Respect forces the bigger parties on to new terrain. They are not entirely sure what to do about it or what the longer-term electoral consequences will be.

As far as Labour is concerned, Frank Dobson, a former health secretary, is already keeping an eye on the BNP, especially in the north of England. When Mr Dobson is not watching Tony Blair with a wary despair he heads northwards in a semi-official capacity, making discreet visits to Burnley, Oldham and other nearby towns. In the south of England, the minister Lord Bassam of Brighton is working on a strategy to counter the rise of the Greens. The Greens performed well enough in the local and European elections to suggest that they could deprive Labour of some seats in a general election. Meanwhile the Conservatives are sweatily anxious about the threat posed by UKIP. A decent showing from the anti-European party at the general election could lead to a further calamitous loss of seats.

The impact of the smaller parties and the frailty of the big two can be seen in the neurotic anguish over the looming by-election in Hartlepool. Labour fears it cannot keep what should be a safe seat. Young aspiring candidates are being advised to keep well clear. As usual in by-elections the Tories are working on the assumption that they do not have a hope of winning and would probably raise a glass if they came a decent third. This means Charles Kennedy should be rubbing his hands in gleeful anticipation, but even the Liberal Democrats are not immune from the rise of smaller parties. They worry that UKIP will cause an unpredictable stir.

The rise of the smaller parties is partly to do with the failure of the bigger two. The Conservatives have had an identity crisis for more than a decade now. Since the fall of Margaret Thatcher they try out different identities most days of the week: "We are still a Thatcherite party ... No we are not, we are compassionate Conservatives with leaders who wear baseball caps ... We are passionately Eurosceptic ... Oh no, we don't talk about Europe because when we do we tend to give the impression that we are deranged ... We talk about Europe quite a lot, and have a moderately sceptical approach."

Such traumatic, unresolved introspection is a gift for parties with simplistic right-wing messages. How easy it is for voters on the right to turn away from a party tortured by self-doubt to ones with seemingly passionate convictions on Europe, asylum and crime.

Labour also has an identity crisis, in some ways deeper than the one overwhelming the Conservative Party. At least Conservatives, from Ken Clarke to Iain Duncan Smith, place themselves on the right of the political spectrum. Under the leadership of Tony Blair, Labour has moved far enough to the right to make it far from clear where the party stands on the political spectrum. Mr Blair has made competence the main dividing line with the Conservatives. Indeed he recently declared that the big idea behind New Labour was economic competence and social justice. As no political party advocates policies based on economic incompetence and social injustice there are ideological limits to Mr Blair's political philosophy. His tame defensiveness has left large amounts of political space on the centre-left.

This is mainly occupied by the Liberal Democrats, although they have contrived an identity crisis too. They are to the left of Mr Blair but cannot admit it because they seek votes from the right. The performance of the Liberal Democrats at the next election is one of the more unpredictable factors in the political equation. In the last two elections they have been part of an anti-Conservative force, explicitly so under the leadership of Paddy Ashdown and by implication under Charles Kennedy. But over the past year they have won by-elections in Labour territory and have clearly benefited from the disillusionment of former Labour supporters who opposed the war. If these Labour voters do not return to the fold by the time of a general election, Mr Blair will limp to a third victory at best.

With the Greens also making some inroads, the relatively modest level of votes New Labour secured in 1997 and 2001, fewer than the Conservatives won in 1992, will prove to have been a peak.

Smaller parties have flourished fleetingly in the past, enjoying a moment or two in the limelight before imploding pathetically, swept aside by the Labour and Conservative giants. In the 1970s the National Front was making similar waves to the BNP. The Greens soared in the 1988 European elections, forcing even Mrs Thatcher to affect a brief interest in environmental matters. Like other smaller parties they failed to build on their success.

There is, though, a big and understated difference now. Nearly all elections in Britain are conducted on the basis of proportional voting systems, which give greater sustained opportunities to smaller parties. It is only in general elections for the Westminster Parliament that voters put a cross against a single candidate in a straightforward, first-past-the-post contest. This has been a stealthy constitutional revolution. One of Mr Blair's early concessions to Paddy Ashdown was the introduction of a new voting procedure for European elections. The Scottish Parliament and Welsh Assembly are elected on the basis of limited proportional representation. For the mayoral contest in London and the London Assembly, convoluted proportional systems come into play.

Indeed so complex are these various voting procedures that I continue to meet highly intelligent people in London who claim to have found the task of voting last June almost impossible. The ballot papers baffled them. Whatever the logistical problems, these voting systems breathe life into smaller parties, making it much less likely that they will fade away.

There are some who will regard this new development as an example of a robust new pluralism, arguing that voters have real choice as more parties thrive. They are being naively optimistic. Most of the smaller parties present glib solutions that rarely stand up to scrutiny. Quite often they are poorly and eccentrically led. Of course the generalisations do not apply in every case. There are important differences between the smaller parties. Some have noble aspirations. Others are brutally ugly. But in most cases voters are not being astute political consumers in opting for these parties. Instead they are accepting the clichés that most mainstream politicians are up to no good.

The rise of small parties is a depressing sign of decay in the bigger ones and a refusal on the part of voters to face complicated choices. When small parties flourish in Britain, democracy is weaker. Yet under the new voting systems, smaller parties are here to stay.

s.richards@independent.co.uk