Things might be changing. We have been offered a mortgage with HSBC with as little as only a 10% deposit. We are putting more down but I thought I would post that a 10% is possible. You need to pay a slightly higher rate though.
You need at least 3 payslips and you need to be in full time work on a permanent contract. If you been out of the UK for longer than 12 months you won't get a mortgage until you;ve been back 12 months at least so renting is a good option.
Another tip. Lots of houses up for sale and to rent. It's worth looking to see if you can rent a house that you might want to buy later. A good, fair offer is usually accepted and it saves you having to move twice!