David Cameron is to reveal tough new laws to clamp down on extremists as details emerged about covert propaganda schemes to combat the lure of Islamic State in the UK.

The Prime Minister will announce new powers to ban organisations, gag individuals and close down premises used to "promote hatred", in measures to be included in an Extremism Bill in the Queen's Speech on May 18, The Times said.

Meanwhile the Home Office defended the work of the Research, Information and Communications Unit (Ricu), challenging the "warped ideology" of IS, also known as Daesh, which included activities carried out in secret away from "the media glare".

Downing Street refused to comment on the Extremism Bill, but The Times said it would extend vetting rules so employers will be told of known extremists to prevent them from working with children and other vulnerable groups or from carrying out roles in "sensitive areas".

There are also plans to extend Ofcom's powers to suspend broadcasts deemed to include "unacceptable extremist material".

The newspaper also said Home Secretary Theresa May would shortly launch an independent review of how Sharia courts operated in Britain.

A Downing Street spokesman said: "We cannot comment on what may or may not be in the Queen's Speech."

The Guardian revealed details of some of the work carried out by Ricu to steer people away from radicalisation.

The organisation often conceal's the Government's role, the newspaper said, leading to claims it was "deeply deceptive".

One initiative, which portrays itself as a campaign providing advice on how to raise funds for Syrian refugees, has had face-to-face conversations with thousands of students at university freshers' fairs without any of them realising they were engaging with a government programme, the Guardian said.

The Help for Syria campaign has distributed leaflets to 760,000 homes without the recipients realising they were government communications.

Much of the work has been outsourced to a communications company, Breakthrough Media Network, which produced websites, leaflets and social media content with titles such as The Truth about Isis (IS).

The Home Office said Ricu's work could involve "sensitive issues" and some of the organisations it worked with did not want to publicly reveal the relationship with the Government.

A Home Office spokeswoman said: "The battle against terrorism and extremism must be fought on several fronts including countering its twisted narrative online and in our communities. The need for this work is recognised at a national and international level.

"As the Prime Minister has said, we face a generational challenge and it is vital we work in partnership with communities, civil society groups and individuals to confront extremism in all its forms. This has been a key part of the Government's counter-terrorism strategy since publication of the Prevent review in 2011.

"We are very proud of the support Ricu has provided to organisations working on the front line to challenge the warped ideology of groups such as Daesh, and to protect communities.

"This work can involve sensitive issues, vulnerable communities and hard to reach audiences and it has been important to build relationships out of the media glare. We respect the bravery of individuals and organisations who choose to speak out against violence and extremism and it is right that we support, empower and protect them.

"Our guiding principle has to be whether or not any organisation we work with is itself happy to talk publicly about what they do. At the same time we are as open as possible about Ricu's operating model, and have referenced the role of Ricu in a number of publications and in Parliament."

Ricu was set up as a cross-government initiative in 2007 as part of the response to the July 7 terror attacks in 2005, and works by bringing together civil society groups, spin doctors and industry experts.

In the 2011 review of the counter-extremism Prevent strategy the Government identified a need to produce "sharper and more professional counter-narrative products" and to "engage a wider range of credible civil society partners".

At the launch of the counter-extremism strategy in October 2015 Mr Cameron said: "We will actively support mainstream voices, especially in our faith communities and in civil society. That means supporting all those who want to fight extremism, but are too often disempowered or drowned out in the debate."

Critics of Ricu's work warned it could cause serious damage to relations with Muslim communities.

Human rights layer Imran Khan told the Guardian: "If the Government wants its Muslim citizens to listen to it, it needs to be trusted. And to be trusted, it needs to be honest. What is happening here is not honest, it's deeply deceptive.

"Furthermore, this Government needs to stop thinking of young British Muslims as some sort of fifth column that it needs to deal with."

The reports about the work to counter extremism in the UK came as it emerged IS in Syria had been secretly colluding at times with Bashar Assad's regime.

IS files leaked to Sky News suggest one piece of co-operation was over the ancient city of Palmyra.

The documents also indicated that IS has been training foreign fighters to attack Western targets for much longer than security services had suspected.