15% seems to be about the lowest deposit required (with many lenders wanting 20%). I'd be surprised if you could find any lender wanting only 10% (unless they were offering a commercial mortgage with really high interest rates).
While I'd be happy to see someone prove me wrong, I'd regard 5% as totally impossible.
There are literally a couple of 90% deals on the market and none for 95% or more. So as Chris said, you need to aim for 15%-20% to have any sort of choice of deals.
If you are a first time buyer you may qualify for the new government scheme announced in the budget. That only requires you to raise 5%. Do not know full details but think you have to buy a new property. Have a search on line. May help.
If you can, don't go looking for the lowest deposit you can. It'll only mean paying more in the long run, and the capital reduces oh so slowly until the last bit. Try to reduce payments or term as much as possible, even if it means waiting longer saving up.