So, yet another Conservative constituency will be added the Liberal Democrats' list of "winnable" seats.  At the next General Election the Conservative candidate Bob Neill should expect to be the target of the now standard campaign literature bar chart showing that the Liberal Democrats are on course for winning a victory of historic proportions in his formerly safe, Conservative seat.

Not too much should be read into any by-election result, including this one.  The Liberal Democrats, whose resources are so often stretched when contesting six hundred plus Parliamentary seats, are ruthlessly efficient in garnering their supporters from all over the country when contesting single seats at by-elections.  It would be a fair guess that the number of Liberal Democrat supporters "on the ground" at Bromley and Chislehurst easily outnumbered those of their opponents.  Neither is it an unreasonable presumption that traditional Labour support went obligingly soft and transferred to the Liberal Democrats in a typical protest gesture against their own Government.  A high profile UKIP candidate Nigel Farage again showed how easy it is to drain Eurosceptic protest votes away from the Conservatives in a contest that "does not really matter".

The Conservatives fielded a traditional, white, middle-aged lawyer, Bob Neill.  The Liberal Democrat candidate, Ben Abbotts, was a young, good-looking professional politician.  Mr Neill provided hostages to fortune by contesting the election whilst being a serving member of the London Assembly and holding an office that he would be prescribed from retaining once elected and "sworn in".  This enabled his opponents to claim that he was not the best candidate because he could not concentrate on the job of being a Member of Parliament.  It was spun further by the suggestion that by virtue of holding a prescribed office, any poll victory by Mr Neill could be overturned by the High Court, so a vote for the Conservative candidate would be a wasted vote.

All these factors and more, deflated the Conservative vote. The slump in the Labour vote, the presence of Mr Farage and the Liberal Democrats fielding a very strong, highly professional politician in the person of Ben Abbotts contrived to inflate the Liberal Democrat share of the vote.  The Liberal Democrats will be very happy today and the glow of that euphoria will last for a long time to come but  it is a false dawn. That red glow in the sky more is likely to portend the bonfire of their dreams.

Come the General Election, with diminishing support in terms of manpower and finance, the Liberal Democrats have to defend their seats against a resurgent Conservative Party that has reconnected with the electorate.  They will have to target their seats very carefully or else lose more seats to the Conservatives than they gain.  No doubt Nigel Farage and Ben Abbotts will drift to constituencies identified as more likely to yield success than Bromley and Chislehurst.  Labour support will "firm up" when a "real" election is held.  Conservative Eurosceptic voters who flirted with UKIP yesterday will not likely do so at a General Election, particularly if to do so might ensure an historic forth-term victory for Labour, or hand the seat to the rabidly pro-European Liberal Democrats.

At the next General Election, the Liberal Democrats would be wise to concentrate their efforts upon their own marginals, for example Romsey, Winchester and Eastleigh, leaving alone such phoney marginals of the likes of Bromley and Chislehurst.