There was never any doubt that Pichegru and Georges and the others were sent to France by the British government to act against the French government in the same way as the French stirred up trouble in Ireland. The question is whether the British government were actually supporting assassination attempts. Evidence in that area is always likely to be hard to come by and I understand (ref Hall 'General Pichegru's Treason') that in general officials refused to have a part in assassination plots while, admittedly, continuing to fund the people who had suggested it.
>Further evidence of direct British government involvement in the 1804 plot to murder Napoleon lies in several letters, the first written on June 22, 1803, from a Mr Walter Spencer to Lord Castlereagh, a senior British cabinet minister, asking for the repayment of £ 150 for himself and £ 1,000 for Michelle de Bonneuil, a royalist plotter with several identities who is known to have met Louis XVIII’s brother the Comte d’Artois (the future King Charles X) in Edinburgh during the Amiens peace. Spencer said the money had been advanced ‘relative to a political intrigue planned by Lord Castlereagh to abduct Bonaparte in 1803’, which was co-ordinated by Mr Liston, the British envoy to The Hague (38) (Plots to ‘abduct’ Napoleon at this time were transparent covers for his assassination.) Although there is nothing directly incriminating from the government side in the exchange – as might be expected – George Holford, a member of parliament who was Castlereagh’s closest friend in politics, wrote to Spencer saying that if he would ‘take the trouble of calling in Downing Street his Lordship will see him upon it’. This would hardly have been the case if Spencer had been a crank.<
The letter written in June 1803 can't really be direct evidence of a plot in 1804, it would be more relevant to know the dates of later letters. However, the evidence from the trial was that it was in June 1803 that the royalist agents were starting to make their arrangements in Normandy. Georges stated in his interrogations that he had come to find out the prospects for a movement against Bonaparte and that if he considered it appropriate he would have sent for one of the princes and then acted under his orders, an attack in force against the First Consul was one of his options but he consistently rejected the idea of an assassination. I do not know what evidence there is that 'abduction' was used as a euphemism for 'assassination'. There was no proof that any assassination was planned though clearly Georges and his gang were up to no good.
The difficulty when you get into espionage and counter-espionage is that it is very difficult to know who to believe; how many plotters were connected with each other; how many were double agents; how many of the plots were genuine or even how many of the plotters actually existed - particularly given the tendency to use several names. That Castlereagh agreed to see Spencer might look suspicious but might mean he just wanted to know what he was supposed to be implicated in - he could have paid the man off without inviting him to visit.