Any obvious solutions?

Thanks for all the suggestions everyone. In the end I went for the ALU-FIX
10 concertina loft ladder which whilst not the cheapest, was the only
practical solution due to the position of the hatch.

Just finished fitting it - took about four hours but I did also a) assemble
a new work bench and b) strengthen the existing hatch frame. The concertina
ladder is quite a scary piece of equipment with some strong springs that
hold it up in place. It sort of hangs over the opening, attached to a
vertical wooden board. Without extending/strengthen my existing hatch, this
would have been rocking on a 2" wide strip - didn't feel safe at all!

The plastic hook lasted all of two uses - as useless as a chocolate
fireguard!

So now I can move all the crap from downstairs ready for starting the
bathroom next weekend. Ho hum!

Cheers, Rob.