A new Scottish anti-drugs strategy by this summer will see a sharp move away from dependence on methadone to treat addicts, with more rehabilitation effort.

It is aimed at more Drug Testing and Treatment Orders (DTTOs) in court sentences, possibly extending to Children's Panels. Ministers also want to crack down on drugs in prisons with more testing, but there is no sign of action on helping the estimated 50,000 children who live with drug-addicted parents.

The pledges have been made in letters to opposition parties by Fergus Ewing, minister responsible for drugs policy, as part of the Budget negotiations which drew to a close with last night's vote.

Conservatives claim victory with a government promise to review the spending on drugs treatment with an expectation it will rise from next year, though Labour and LibDems have also been in talks with Mr Ewing.

The initiative represents a significant shift towards a new cross-party consensus around the handling of Scotland's serious drug problems.

According to addiction expert Professor Neil McKeganey of Glasgow University, the political shift is a challenge to those who work in the field to reduce dependence on methadone, with a switch to expensive and difficult measures to get people off drugs.

Mr Ewing wrote to Bill Aitken, the Conservative justice spokesman, promising there will be more emphasis on promoting abstinence and more residential rehabilitation. Officials are now starting a review of drugs budgeting , to report by spring next year.

The DTTO plans are with strong provisos that Lothian and Border pilots will have to prove their effectiveness before they are used in all courts. Drug test orders for children will form part of a separate youth justice strategy, also due by summer.

Mr Ewing told LibDem justice spokeswoman Margaret Smith he wants the strategy to respond to her call for more education to warn against drugs. She has also secured a promise that a team of drug experts will advise on the new strategy.

Mr McKeganey said there has to be more done for children who live with addicts. "They live in desperate circumstances and are among the most vulnerable people we have," he said. Drug workers will need re-training, he added, and with around 25,000 Scots on methadone, there will be difficult decisions to be made about who takes priority for expensive treatment.

A Scottish Government spokesman said last night the letters included only some of the strategy and meeting the needs of addicts' children would be part of it.