OP
Darkwood
NO but they did make sure a 16amp commando socket was fitted so would be forgiven that thinking a 16amp circuit max woulde exist otherwise the user would be powering from an unsound supply.
Also as with all portable appliance by removing the original manufactured plug you would nullify your guarantee and insurance for the washer with that you have uprated whatthey percieve would only be a 16a supply
However what you are stating indicates there is no legal reason why you cant
What a load of crap removing the plug from an appliance does NOT! effect the guarantee its a myth and stems from some firms using illegal practices of saying their cant repair or replace the under warranty product as you have take the plug off...
If a plug was changed and due to incorrect or badly terminated new plug or spur etc the appliance suffered damage then and only then can the manufacturer void warranty and of course they need to prove it...
As the jet wash is load limited (fixed) fitting a 32amp plug cannot effect the use and safety of the product in any way and will not in this case be an issue that the plug over-rates the flec you connect to it.