A future Conservative government will bring in "boot camps" for unemployed young people aged between 18 and 21 who refuse to take a job, Chris Grayling, the party's welfare spokesman, will say tomorrow.

In a significant hardening of Conservative policy towards welfare claimants, he will announce the abolition of benefit payments for any able-bodied person under 21 who is out of work for more than three months and who refuses to go on a compulsory community service programme or a "boot camp" training course aimed at improving their work discipline and giving them basic skills to get a job.

Grayling plans to ask private sector companies and voluntary organisations to run the intensive training centres - with the £5,000 it costs to support a single person on the dole being offered to the company or voluntary group once the person has been in work for one year. Individuals will be expected to report to the centre every day for an intensive training programme.

Some private companies - notably the Australian firm Work Directions - have successfully bid for business from Labour on a " bonus basis" to get the disabled back to work.

Grayling will say: "We plan to introduce much tougher rules for young people under the age of 21 claiming jobseeker's allowance. For this group, the welfare to work process will start much earlier. There will be employment 'boot camps' and community work programmes for those who don't find a job. Staying at home doing nothing will be a thing of the past."

Under the Tory proposals, unemployed young people who do not find a job within three months will be referred automatically to a specialist employment provider, where they will be expected to take part in an intensive programme of work-related activity. If they spend 12 months out of work, they will then be moved on to a full-time community work programme lasting a further year.

The hardening of Tory attitudes towards the unemployed will be combined with much tougher polices than Labour to get single parents and the disabled back to work, and a big move to privatise provision to help the unemployed. Ultimately the move could see the end of state-funded Jobcentres and a big reduction in size of the Department for Work and Pensions, which has already lost 30,000 jobs under Labour.

Grayling will also announce a clampdown on those who misuse government training programmes. This follows disclosures that government claims to have retrained three million people on the New Deal were false after 750,000 people were found to have been on the training programme twice, and a few dozen as many as six times. Some people also avoid going on the programme by signing off benefits for a week when they are due to go on the programme, only to sign on again a short time later.

Grayling will say: "Under our proposals, there will be no room for that kind of manoeuvre. In that situation, the clock will simply be frozen. It won't be reset to zero again. With this approach, for those who are struggling there will be real help. For those who are not, there will be no opt-outs. We will end the street-corner benefit culture among young people which this government has left to fester for the past 11 years."

The measures should cut crime because people would not be hanging around with nothing to do, Grayling will say. For those who decided to embark on a life of crime because they would not work and could not get benefit, there would be "zero tolerance from the criminal justice system".