You usually need a deposit of at least 5% to get a mortgage.
For example, if a mortgage has an LTV of 95%, you'll need a 5% deposit. On a £150,000 property, this would mean a deposit of £7,500. You'd get a mortgage for the remaining £142,500.
You can find 95% mortgages for first home buyers from a wide range of lenders in our comparison tables.