What do you mean?
Mircosoft surface Pro coming out soon. They are saying $899, so there is a chance cost around £700.
I don't think there are many convertible at £700
You can have a look at Acer Iconia W700
http://www.amazon.co.uk/dp/B00A0J08...de=asn&creative=22206&creativeASIN=B00A0J08UI
http://www.amazon.co.uk/dp/B009T69O...de=asn&creative=22206&creativeASIN=B009T69O4Y
(laptopdirect sell it £5 cheaper)
Or alternatively you can consider Asus S200 (i3 version). It is a laptop with touch screen.
It is just £450 at ebuyer
Convertible tablet/ laptop reviews
http://www.trustedreviews.com/best-windows-8-laptops-tablets-convertibles-and-pcs_round-up