Cameron finds Davis in need of serious election opponents

David Cameron joins the Conservative candidate David Davis at a school in Melton, near Hull, last night (PA)

David Cameron must wonder what he walked into last night. The Conservative leader made a whistle-stop visit to Haltemprice and Howden, eight days ahead of the by-election called following the resignation of his former shadow home secretary, David Davis.

The attention being afforded another candidate, David Icke, the conspiracy theorist who once claimed the world was governed by a shadowy cabal of shape-changing alien lizards, highlights the problem facing Mr Davis in his one-man crusade to defend cherished freedoms stretching back to the Magna Carta.

While Mr Cameron gladhanded local Tory dignitaries, Mr Icke held forth to the gathered media on the "co-ordinates" that are guiding the world towards fascist dictatorship, explaining his "Big Brother" conspiracy – a view of the world which encapsulates everything from the evils of Robert Mugabe to the dangers of the Lisbon Treaty.

The failure of either the Liberal Democrats or Labour to stand in the East Yorkshire seat has left Mr Davis with an embarrassing shortage of serious opponents to engage in the very debate he sought to spark. Instead he faces 25 rival candidates – the longest ballot paper in electoral history – many of them highlighting a bewildering array of single-issue causes. Among them is a lads' mag model who holds the title of Miss Great Britain; a farmer seeking to promote the use of the abacus in schools; and a Eurovision Song Contest double-loser.

Mr Cameron joined his former leadership rival for a debate on civil liberties at South Hunsley School in Melton. The Tory leader stuck rigidly to script, insisting Mr Davis enjoyed his full backing and that his decision to spark a by-election was not a distraction from the main cause of beating Labour. "I am delighted to be here," he said. "I said I would come and campaign with David and we are both going to be talking about the same important subject."

But he told an audience of schoolchildren: "If everyone called a by-election I wouldn't have much of a Shadow Cabinet." The show of unity failed to convince one audience member, sixth-former Harry Young. "I couldn't see any tension but I think they were probably trying to hide their difficulties," he said.

Mr Davis is defending a 5,000 majority from the last election and no one seriously expects him to lose. He insists his stance is proving popular with the voters locally and has propelled the issues to the forefront of political debate nationwide. A Shadow Cabinet minister is scheduled to visit the constituency every day between now and polling, though in truth fewer than half will make the journey northwards, according to a Conservative Party source. One of the candidates some believed might actually pose a threat to Mr Davis is Jill Saward – the victim of what became known as the Ealing vicarage rape in 1986.

As one of the first sex attack victims to waive her right to anonymity, her arguments on law and order carry more authority than most. She opposes Mr Davis on his demands to role back the frontiers of the surveillance state, demanding the DNA database be made national while seeking more CCTV cameras and an end to the right to silence.