THE days of the lonely artist slaving away in the garret end today with the inception of the first trade union for visual artists.

More than 150 artists from as far apart as Stornoway, Inverness and Edinburgh are expected to converge on the Scottish Trades Union Congress headquarters in Glasgow to confirm the constitution of the Scottish Artists' Union.

Organisers say that, if successful, the scheme could expand into England where similar problems are faced by many artists.

After years of debate, including the Glasgow visual arts forum, the initiative is to become a reality.

Bill Speirs, general secretary of the STUC, will meet artists as they take the unprecedented step that brings the visual arts into line with actors and musicians, traditionally represented by Equity.

The union, once formed, will consider affiliating with the STUC or joining a larger union as an independent branch.

David Cook, manager of Wasps artists' studios in Glasgow and Edinburgh, said the union would help artists gain public funding, deal with copyright issues and advise them on legal problems they may face with galleries and dealers.

''We were hearing all the gripes about why things are the way they are in the art world, the different funding between art forms, and decided to do something about it. We have now drafted a constitution, membership criteria and a proposal for union subscription.

''At the visual arts forum meeting there were 80 people and we have been receiving applications from people who want to join a union at the rate of 25 a month.''

There are three principal aims: to protect and extend artists' rights, to lobby on behalf of artists, and to deliver practical benefits, such as free legal advice and cheaper insurance.

Mr Cook added: ''Where artists are in a situation where a gallery has treated them badly and they can't afford to take on a lawyer, the union will offer legal advice and help them in that situation.''

One of the first targets for the union will be to tackle unscrupulous art dealers.

It is not unusual for artists to face a fee of 30%-50% commission on their works and to be charged for ''hidden'' items like framing their show.

Lobbying for exhibition payment rights - where a work is on display in a public-funded gallery, but not for sale - will also be set out as a priority.

The grassroots movement is understood to have the support, at least in spirit if not yet in membership, of many well-known artists.

Others involved at the outset include Gerry Morris, a painter with work in the collections of Bob Geldof, Annie Lennox, Ben Elton, and Dawn French; Ann McCluskey, a member of the Society of Scottish Artists and a steering group member of the new union; Ken Palmer, a photographer working in education and multimedia research, and Guyan John Porter, a graduate of Grays School of Art in Aberdeen and a long standing campaigner for an artists' union.

Allan Wilson, the Scottish arts minister, was to attend the meeting but cancelled due to election commitments.