This doesn't sound like a very good idea
Over stretching massively to invest in property caused a lot of people a lot of problems and the general consensus is that the market is far from bottomed out, especially given that the UK has only implemented 25% of the planned spending cuts - not to mention the impending eurozone implosion and the effect that will have.
I'd keep saving hard, as your level of deposit increases the market will continue to fall and you can really lowball some offers in a couple of years.
for a good mix of info/pessimism/realism/schadenfreude check out www.housepricecrash.co.uk
post your plans there and see what they say. You should be doing some really heavy research on all this. gl.