The calculated decision throws a question mark over the long-term future of general- election press conferences - which are now so tightly stage- managed that they have already lost much of the bite they had in the Seventies and Eighties.
In Wirral South this week, only two formal press conferences have been called; one for John Prescott, Labour's deputy leader, and the other for Liverpool's Liberal Democrat MP David Alton to declare his personal support for Flo Clucas, the party's by-election candidate.
The traditional by-election routine has been for the main parties to start their day - as in general elections - with press conferences that are staggered to enable the press pack to go from one to the other to put the questions of the day and assess candidates' performance.
Over the years, however, press conferences have been turned into a blood sport for hungry hacks, with reporters searching out runt candidates and ripping them apart on a slow rack. In the 1981 Crosby by-election, the Conservative candidate, John Butcher, was so dreadfully treated by the daily press baiting that he shook at the prospect of the daily torture.
Candidates who survive the routine - like James Clappison, in the 1990 Bootle by-election, and Michael Bates, in the 1991 Langbaurgh campaign - might well deserve their current frontbench office on that basis alone.
When Mr Prescott held his press conference in Wirral South on Monday, the Labour candidate, Ben Chapman, was so closely protected by his minder, the Labour MP Ian McCartney, that he could hardly get a word in edgeways. At a meeting with Tony Blair on Wednesday, Mr Chapman was given the part of non-speaking extra.
But if Mr Chapman has been given a walk-on part, the Tory candidate, Les Byrom, was carried about as a wooden dummy for Cabinet ventriloquists.
The Conservativs have held no formal press conference, confining themselves instead to stunts - lsuch as Brian Mawhinney's unveiling of propaganda posters in a car park on Tuesday - or walkabouts.
In such circumstances, many of the politicians' reported words are eavesdroppings from snatched, walkabout conversation, or extensive media interviews, which tend to revolve around a repetition of the day's pre-ordained sound- bites.
A Labour spokesman said yesterday: "We'll be having press conferences from time-to- time, and we're expecting to have them pretty well every day during the general election." There are no guarantees there.
The Conservatives are already staging London press conferences, in a practice run for the general election. But compared with the free-range days of Margaret Thatcher's campaigns, they are tame, regimented affairs.
While Baroness Thatcher enjoyed follow-up supplementary questions, the last election saw strict enforcement of rationing, with only one question each for hand-picked reporters.
In the 1992 election, Conservative press conferences, aggressive questioners like Alastair Campbell, then of the Mirror, now Tony Blair's press secretary, were effectively frozen out of the regular daily questions, and attempted follow-ups were largely blocked.
t Labour's lead over the Conservatives has dropped by three points to 15 points, according to a Gallup poll carried out in the last week.
However, a bigger survey carried out in January shows Labour 17.5 per cent ahead of the Conservatives with 50.5 points to their 33.Reuse content