Sources said it would make it easier for the police to prosecute the likes of Anjem Choudary and his followers

New criminal offences designed to ensnare Islamist hate preachers are being drawn up by ministers, the Daily Mail understands.

Downing Street is planning a major counter-extremism offensive if the Conservatives win the general election on June 8.

Sources said ministers were determined to ‘drive extremism out of society’. The proposals pre-date the Manchester terror attack, but the bombing will give them further impetus.

The new offences will target extremists who attempt to skirt the law by endorsing radical views but stop short of directly advocating violence.

Sources said it would make it easier for the police to prosecute the likes of Anjem Choudary and his followers.

A new government agency – a Commission for Countering Extremism – would identify extremists, ‘counter’ their message and promote British values.

A Conservative source said: ‘Just like racism, extremism can be defeated. But it will take sustained effort to change cultural and social norms amongst certain sections of the population.

‘We know that extremism is not confined to any one community and we want to use a Commission, like the Commission for Racial Equality, to drive extremism out of our society.’

New powers to compel tech companies to hand over encrypted data to the police and security services are also being drawn up. They would allow security officials to insist services such as WhatsApp and Facebook remove all encryption from suspect messages.

It came as ministers were urged to expand the use of control-order style powers. Former government counter-terrorism adviser Lord Carlile said greater use of the orders against extremists might have prevented the Manchester bombing.

Currently, only seven extremists are subject to T-Pims – Terrorism Prevention and Investigation Measures, civil orders which put legal restrictions on the activities of terror suspects.

Lord Carlile said: ‘T-Pims should be used in a proper way, by being toughened up with a relocation package.

'I think there is a strong case for using them much more extensively as long as they are strong enough.’

Downing Street is planning a major counter-extremism offensive if the Conservatives win the general election on June 8

He said Islamists who had been to Libya – which he described as an ‘international testing ground’ for Islamic State recruits – should be considered for T-Pims which ordered them away from their communities.

Manchester bomber Salman Abedi had recently returned from the North African country.

Last night Home Secretary Amber Rudd vowed to pour more money into Britain’s flagship counter-extremism programme when it is relaunched next month.

Insisting the Prevent strategy was a success, she said it had stopped 150 people travelling to Syria last year and that 142 community organisations were doing ‘good work’.

The Prevent scheme aims to stop people being drawn into or supporting terrorism.