Just in case anyone else is thinking of trying this, I thought I would give a quick update.
Laid out the membrain yeaterday with a combination of pegs and bricks/ part paving slabs every 6 feet.
It was not made any easier as the weeds were in tussocks, would have been easier if I had been able to strimmer.
Went up this morning to find the wind had got under about 50% of it, so have now added just about everything heavy I could find on the plot and hope this will hold it.
So whilst it was undoubtedly quicker than the card and compost option, I am not entirely confident that it will be effective and since the pegs were next to useless I still need more ballast to hold down the fabric on the remainder of the plot.