The Sussex planespotter found guilty of aiding and abetting a group convicted of spying in Greece should be acquitted, an appeal heard.

Christopher Wilson, 47, of Erica Way, Horsham, was handed a one-year suspended sentence, after being arrested last April.

The public prosecutor told an appeal hearing today that Mr Wilson and five fellow planespotters should be acquitted but he said convictions should stand for six other Britons, who were previously convicted of the more serious charge of espionage.

Defence speeches were set to begin before the panel of judges retire to consider their verdicts.

If they accept the prosecutor's recommendation, then Mr Wilson, Michael Bursell, Lesley Coppin, Wayne Groves, Steve Rush, and Michael Keane would be acquitted.

Earlier the appeal hearing heard Squadron Leader Nectarios Samaras, taking the stand for the prosecution, describe the planespotters "strange behaviour", and told the court how the men and women took copious notes of planes and military hardware deemed "sensitive" by the airforce.

He singled out Paul Coppin, owner of Touchdown Tours in Sussex, which organised the trip, for taking "more precise, more detailed" notes than the other enthusiasts.

Asked to explain why his note-taking was "more expert", Mr Coppin, 46, told the court that his pads contained lists of planes he had yet to see; he had got the data, including serial numbers of various aircraft, from the European Airforces' Directory - the bible of those who shared his hobby.

All the group deny any wrongdoing, saying the tour had an official invitation to attend an air display in Kalamata.

Sq Ldr Samaras told the court he had been alerted to watch them, because they had been seen taking notes elsewhere, but agreed they entered the base legally because it was an annual open day.

Attributing an initial accusation of espionage to "over-zealousness" of the officers, Yiannis Zacharia, the spotters' lawyer, said his clients had never been warned not to take notes.

He said: "There were only signs forbidding photography.

Mr Zacharia also told the court: "You the officers say not even a mosquito can get into one of these airbases, when in fact a popular television soap opera was recently filmed on the base here."

Yesterday the presiding judge, George Efstathiou, vigorously cross-examined prosecution witnesses, two officers who arrested the group in Kalamata, while the Britons sat glumly in the dock.

Unexpectedly, the British ambassador, David Madden, appeared at the Peloponnesian courthouse yesterday to "reinforce the strong interest of our Government".

Mr Madden, believed to be the first ambassador to attend a trial of British citizens abroad, said: "We very much hope there is a positive outcome. I believe the planespotters were pursuing their hobby."

It was the first time in Greece that EU nationals had been found guilty of spying on military installations.

The six Britons convicted of spying are: Antoni Adamiak, 37, from London; Graham Arnold, 39, of Ottershaw, Surrey; Paul Coppin, 46, of Mildenhall, Suffolk; Garry Fagan, 31, of Kegworth, Leicestershire; Andrew Jenkins, 33, of York; and Peter Norris, 53, of Uxbridge, west London.

Two Dutch men travelling with the group were also convicted of spying and face the same sentence.

The six found guilty of aiding and abetting are: Mr Wilson, Mr Coppin's wife Lesley, 51, also of Mildenhall; Michael Bursell; Wayne Groves, 39, of Tamworth, Staffordshire; Steve Rush, 38, of Caterham, Surrey and Michael Keane, 57, of Dartford, Kent.

Mr Keane has not returned as he was advised against it on health grounds.