An ex-RAF man prosecuted for refusing to buy a river navigation licence for a “houseboat” in Hartford that can’t be moved won a landmark victory at the Court of Appeal on Friday.

Glen Parker, who served tours in Iraq and Afghanistan before retiring, fell foul of the Environment Agency after failing to register his houseboat, The African Queen.

His aquatic home is sited near the Great Ouse, at Hartford Marina.

River navigation licences are issued by the agency at a cost of £400, but Mr Parker took a determined stand and insisted he does not need one.

The Environment Agency prosecuted him, but the ex-serviceman would not give an inch even when threatened with a possible criminal record.

In a decision which broke new legal ground, three senior judges at London's Appeal Court backed Mr Parker against the Environment Agency.

They ruled that the African Queen, which is permanently attached to the marina's bed, is not “a vessel” and does not need a licence.

Lord Justice Lindblom said the African Queen was built on a polystyrene and concrete “raft” and secured to the marina bed by poles at its corners.

It was connected to mains electricity, sewage and water and Mr Parker paid council tax on his houseboat.

As well as having “no means of propulsion”, it had no keel or ballast and would need two working boats to move it, he added.

The African Queen, whilst “a home on water”, was not designed to “propelled or moved” across the water.

On a “realistic view of the facts”, and given the “ordinary meaning” of the word, Mr Parker's home is not a vessel, the judge concluded.

Mr Justice Teare and Mr Justice Holroyde agreed that the Environment Agency's appeal against a judge's earlier decision to clear Mr Parker should be dismissed.

The decorated veteran explained outside during the case that his water-borne home is more akin to a “static caravan” than a standard houseboat.

The 58-year-old, who was joined in his campaign by another houseboat owner, Christopher Gibbs, said around 50 other home owners on the marina were in a similar predicament.

Mr Parker, who was at risk of being hit with a £1,000 fine and a heavy legal costs bill if he lost the case, added: “I didn't expect this when I retired”.