HE is one of Scotland's seminal modern artists whose sculpture of a running clock greets people arriving by bus into Glasgow.

Now the work of George Wyllie, is to finally have its place in the National Galleries of Scotland collections.

Wyllie, who created the Straw Locomotive and the Paper Boat, as well as the Running Clock outside the city's main Buchanan bus station, celebrates his 90th birthday today.

A year-long event, the Whysman Festival, is to be staged in his honour and today he receives plaudits from figures such as Alan Cumming and Sir Sean Connery.

However, it is the newly opened dialogue between the Friends of George Wyllie, the group set up to secure his legacy as one of the most influential and popular post-war Scottish artists, and the National Galleries which is giving his supporters cause for quiet celebration.

The NGS do not hold a work by Wyllie in their contemporary art collections and his work has not been included in their large sculpture show at the Gallery of Modern Art in Edinburgh.

However, John Leighton, the director-general of the galleries, and Simon Groom, director of modern and contemporary art, have met the Friends and agreed in principle to have works by Wyllie on loan at the galleries, with the possibility of an acquisition at some point in the future.

A spokeswoman for the Friends said: "We had a good meeting with the directors about George generally, and getting work into the collection and they were very supportive.

"They are now looking at George's pieces, having a loan and seeing what works, and in the longer term, making a purchase of a piece."

A spokeswoman for the NGS said: "I can confirm the National Galleries of Scotland have had discussions with the Friends of George Wyllie. The idea of a loan of his work to the Scottish National Gallery of Modern Art has been discussed and this is a possibility we will look into further in the course of 2012."

Wyllie now lives in a care home and much of his work is in storage.

Yesterday, the Friends of George Wyllie presented the artist, who says he puts a question at the heart of everything he creates, with a question-mark shaped cake.

Louise Wyllie, his daughter, also announced that Alan Cumming, Sir Sean Connery, Bill Paterson, Liz Lochhead the Makar, and Murray Grigor will all contribute to a year of celebrations of his life and work in the Whysman Festival.

As part of the festival, a retrospective exhibition – a first for Wyllie – will be held at the Mitchell Library in Glasgow in November.

Yesterday Cumming, a star of stage and screen, said: "I have admired George's work since 1987 when he stunned Glasgow with a straw locomotive hanging from the Finnieston Crane.

"It was an act of whimsy, bravado and passion that connected on an emotional level with the Scottish people. It changed my view of what art could be."

Grigor, the film maker, who describes Wyllie as "one of the most popular yet officially misunderstood artists in Scotland" has also released a new DVD of his award-winning 1990 film for Channel 4, The Why?sMan, starring actor Bill Paterson, in time for his friend's landmark birthday.

Sir Sean Connery, who first met Wyllie in the 1970s, said: "George Wyllie welds the humour of Chic Murray into artworks which are at once surrealist and wry reflections on our current loss of engineering innovation, which once made the west of Scotland the workshop of the world."

Ms Wyllie added: "When my father went into a care home, my sister and I were left with the task of looking after his legacy.

"The Whysman Festival will start this process off in a very George Wyllie-esque way.

"We are keeping my father updated and he is pleased to think his work will be reaching out to people again.

"That's what he has always been about. There's a generation of young people who don't know about my father's work – we want to change that."

The Friends of George Wyllie, set up by the artist's daughters, are now working on ways of securing funding for the Whysman Festival.