Offering people with disabilities greater control over the budgets for their own care and support must not be a cover for cuts, according to the trade union Unison.

The public-sector union is urging Scottish councils to continue progress towards greater personalisation of services, but steer clear of the model introduced in Glasgow, as they prepare to introduce new budgets this week.

Having moved more than 1000 citizens with learning disabilities on to the new system – known as Self-Directed Ssupport – in a little over two years, the city is now moving on to implement it for people with physical disabilities and mental health issues who are receiving help.

While supportive of the model in principle, Unison says there have been significant problems and is critical of the council for linking the introductiong of SDS with budget cuts of 20%-30%.

Mandy McDowall, Unison's regional officer in Glasgow, said many people had lost out. "We have not got an issue with SDS and personalisation, but the idea is to give people increased choice and control and that is not what we are seeing.

"Personalisation was meant to create savings in the longer term but not as a short, sharp hit."

A report compiled by Unison on the experience in Glasgow argues that some people who have been assessed for personalised budgets have been awarded grants worth less than 50% of the care they previously received. The report warns: "There's growing concern among service users, carers and workers that behind the rhetoric of increased choice and control, self-directed support is increasingly being used by local authorities in some parts of the country as a cover for cuts in services."

Ms McDowall added: "We haven't had much in yet from the other councils, but my understanding was they were pulling back from the Glasgow model".

The union is holding a conference on personalisation next month in Glasgow for staff, service users and carers involved.

It will explore the experiences of those on the receiving end of the personalisation model, she said. "We hope that will give us a clearer picture."

Glasgow's introduction of the policy for people with physical disabilities has been much smoother so far. But other groups have previously expressed concern about personalisation of support for people with learning disabilities in Glasgow.

Learning Disability Alliance Scotland – an umbrella group of leading charities – has warned it has taken place too fast, and without enough transparency.

Ian Hood, LDAS spokesman, said: "People haven't had a chance to complain or understand the allcoation process."

He said other councils were being "cagey" about what their approach would be in setting budgets this week, but he did not expect many to move as fast as Glasgow in bringing in SDS.

However, he added: "Tieing this into cuts has been a common approach across England and Wales, as well as Glasgow."