SPRINGWATCH presenter Chris Packham reiterated his call for a ban on grouse shooting as a petition to Parliament reached the 100,000 signatures needed to trigger a Commons debate.

A day after being branded an extremist by cricket legend Sir Ian Botham, Mr Packham praised those who signed the petition and insisted ''in the end you can't argue with the truth''.

It comes after the official start of the grouse shooting season, with August 12 known as the Glorious Twelfth.

In an angry clash on the radio Sir Ian, who supports grouse shooting, attacked the TV presenter for not respecting BBC impartiality rules.

Packham said the shoots damage bird of prey populations while Sir Ian suggested the naturalist should not be allowed to publicly take sides because of his status as a BBC employee.

In the wake of the on-air row the petition reached the threshold required for the Commons Petitions Committee to consider it for debate by MPs.

Packham said: ''In the end you can't argue with science, you can't argue with evidence, you can't argue with the truth. And the truth is that people are fed up with this 'tradition', the injustice and the lies.

''One hundred thousand people just started to make the world a better place for wildlife and every single one of them will be remembered for that''.

The petition states: ''Grouse shooting for 'sport' depends on intensive habitat management which increases flood risk and greenhouse gas emissions, relies on killing foxes, stoats, mountain hares etc in large numbers and often leads to the deliberate illegal killing of protected birds of prey including hen harriers.''

The League Against Cruel Sports said the momentum building up against the shoot was now ''unstoppable''.

Its head of campaigns Mark McCormick said: ''The public recognises that the collateral damage from this minority 'sport' based on blasting live birds out of the sky is unacceptable.

''Raptors are being persecuted and hen harriers are facing extinction in England.

''Intensive management of the grouse moors are implicated in environmental damage, devastating floods and wildlife obliteration.

''It's high time a light was shone on the negative impacts of driven grouse shooting.

''We know that a Parliamentary debate isn't guaranteed, but the amount of public concern, the number of experts speaking against grouse shooting and the growing evidence of wildlife persecution surely means that a fair debate must be held as a matter of urgency.''

E-petition sponsor Mark Avery said: ''I'm thrilled that people across the UK have responded to the call to get a debate in the Westminster parliament over the future of driven grouse shooting.

''Now we need our politicians to rise to the challenge and take this matter forward.''