Disgraced councillor Andrew Draper threw a political hand grenade at Waveney District Council yesterday as he resigned from the authority, nearly three months after he admitted drink-driving and assaulting a police officer.

His announcement came as Suffolk police confirmed that he had been charged with a new offence of sending an offensive email and that he had also been arrested for possessing a prohibited weapon at his home.

He is due to appear before Lowestoft magistrates on November 22 over the offenseive email charge and has been bailed over the prohibited weapon, believed to be a stun gun.

Mr Draper's resignation has triggered a by-election which could take place as early as next month. The vote could see the Tories lose power if the residents of Mr Draper's ward at Worlingham, near Beccles, decide to ditch his previous party at the polling booths.

If Labour or an independent who supports them win the ward, which is said to be a Conservative heartland, then it will see the opposition seize power by being able to form a new ruling cabinet.

In the event of Labour winning the by-election the party will have 24 seats compared to the Tories' 22 and will only need Green councillor Graham Elliott supporting them to win an overall majority vote in the 48 seat town hall.

Announcing his resignation Mr Draper said: 'I have today tendered my resignation as a Waveney District Councillor with immediate effect. I have given this much thought and, in light of recent events, have reached the conclusion that it would not be in my, or the council's, best interests to remain.'

In August, Mr Draper – who was voted on to the authority in May –pleaded guilty to drink-driving and assaulting police inspector Stephen Bunn. Following his two convictions at Lowestoft Magistrates' Court – for which he was fined �655 and banned from driving for two years – he resisted calls for his resignation but did quit the Tory group to become an independent.

That decision threw the council into political turmoil as it left the ruling Tories with 22 seats to Labour's 23, leaving it reliant on the support of two independents – Mr Draper and council chairman and Peter Collecott – to win crunch votes.

At May's election the people of the Worlingham ward elected Mr Draper and fellow Conservative Mark Bee with 951 and 1,046 votes respectively.

Worlingham resident Derek Horton, of Broadland Close, recently attended a parish council meeting and challenged Mr Draper over his decision to stay as an independent councillor following his convictions.

The 66-year-old said: 'I just thought what great news it was. I'm really pleased he has gone and would like to know what the reason is to why he has taken so long to stand down.

'Whatever the reason I think that's good news for the people of Worlingham.'

Yesterday, Waveney's Labour group leader. Julian Swainson. said he was pleased Mr Draper had finally gone and that the by-election would be the most important in recent times.

He said: 'Obviously we are very pleased to see that Andrew Draper has done the right thing. We are rather sad it has taken so long but it will enable the people of Worlingham to have a say on the sort of councillor they want. A lot of people have said they have been perplexed he was still on the council for so long after his convictions.'

Colin Law, leader of the council and Waveney's Tory group, said he did not know the reasons his former party colleague had stepped down and he had no power to 'sack' him.