2002 peugeot 307 - peugeot intermittent loss of power - manuka

have an intermittent problem with my 2002 peugeot 307 1.4 petrol.
at around 2000rpm it begins losing power. easing off the accelerator sorts things out for a few seconds then the car starts dragging back again. this goes on until i have to drop down a gear, and then another gear until i can't go any further.
the engine doesn't quit and after dropping through the gears will idle perfectly and from idle i can rev it up to max without a hitch.
it seems as if the engine is failing under (slight) load.
the problem my happen twice in 100 miles or not. leaving the engine off for 10 min or so and all is back to normal. the next time the problem occurs could be in another 100 miles or 700 or whenever it feels.
any ideas anyone?

2002 peugeot 307 - peugeot intermittent loss of power - Gibbo_Wirral

What mileage is your on?

It could be a few things but would be irresponsible of me to suggest or recommend anything without getting a diagnostic check first.

The car's ECU will have logged the fault, along with the mileage when it happened.