An artist acquitted of “insulting the dignity” of the Turkish prime minister has praised an East Finchley colleague who helped secure his freedom.

Michael Dickinson faced criminal charges because his 2006 collage depicting Recep Tayyip Erdogan as a dog on a leash was deemed offensive.

Fellow artist Charles Thomson, 55, who founded the anti-establishment art movement Stuckism, spent two years campaigning for justice for his friend.

The high-profile case was seen as a test of Turkey's tolerance of free speech, with implications for its bid for European Union (EU) membership.

A Turkish court acquitted Mr Dickinson of criminal charges last Thursday, stating that the artwork Good Boy was “within the limits of criticism”. The artist, who spent ten days in “horrific conditions” in jail following his arrest in September 2006, could have faced a two-year prison sentence if found guilty.

Mr Dickinson, 58, a Stuckist who has lived in Turkey for 20 years, said: “I would personally like to take this opportunity to thank Charles Thomson for all his help. Without the backing and support of Charles and the Stuckists the verdict could have been quite different.

“I hope that my acquittal might have an effect on the decisions of the judges of the many other cases where Turkish writers and artists face criminal charges for having expressed their opinions.”

The verdict ended a saga that has included four court hearings and Stuckists calling on both Tony Blair and Gordon Brown to intervene.

Mr Thomson, of Manor Cottages Approach, said: “I felt very strongly that I had to get involved in this trial.

“On a personal level, here was a friend of mine standing up for his rights and likely to end up in a jail where conditions were horrific.

“But there was also an important principle at stake. What I found particularly offensive was that Turkey is being considered for entry to the EU, but is still in many ways an oppressive, barbaric state that treats people horribly.

“What Michael was standing up for was freedom of expression and the right to make comment on political leaders — principles essential for any EU member state.”

Founded in 1999, Stuckism is a controversial art group dedicated to pro-contemporary figurative painting, which regularly campaigns against the Turner Prize. The name was based on a comment made to Mr Thomson by his ex-girlfriend Tracey Emin, who told him his art was “stuck”.

Good Boy can be seen in a Stuckist exhibition at the A Gallery, 154 Merton Hall Road, Wimbledon.