Royal Mail solicitors have given a gallery a stay of execution in the row over mock stamps featuring the Queen wearing a gas mask.

They are threatening legal action over the prints created by artist James Cauty on display at artrepublic in Bond Street, Brighton.

In a letter to the gallery, solicitors demanded the images be removed from display on Tuesday.

Now they have said the prints can remain on show until tomorrow, while the gallery continues to take legal advice.

But the demand for the limited edition digitally created prints has been so high since they featured in The Argus on Tuesday, all 150 could have sold out by then.

The images have also sparked a huge amount of interest in the art world.

The central Brighton gallery has been inundated with inquiries about the stamps. More than 50 individual prints have now been sold.

Sussex-based artist James Cauty, who was a member of the top selling dance band KLF, created them as statement on the war in Iraq at a time when it was suggested gas masks could be re-issued in the face of a possible chemical weapons threat.

Mr Cauty and the art gallery deny there is any breach of the intellectual copyright of the Royal Mail, as the crown, neck-line and hair on the pictures on show in the gallery are different from those on actual stamps. They also point out there is no such things as third class stamps, as featured in Mr Cauty's work.

Gallery chief executive Lawrence Alkin said: "The pictures we have are far bigger than stamps and nobody in their right mind would mistake them for actual stamps."

Andrew Milledge, marketing director of artrepublic, said: "The stamps are artistic and an expression of Mr Cauty's feelings towards the action taken against Iraq. They are still on display in our gallery.

"The Royal Mail had wanted us to take them down on Tuesday, but we have agreed an extension until the close of business tomorrow."

The red, blue and grey stamp pictures are on sale from the gallery for £590 framed, £470 unframed and £1,650 for the full set of three framed.