One of the first lenders to offer products under the Government's extended Help to Buy scheme has taken 10,000 calls on mortgages - almost double the number it would usually expect to take - since last week's launch.

In a series of tweets today, Royal Bank of Scotland said that 5,000 mortgage appointments have been booked with its mortgage advisers both in branches and over the phone.

So far, just a handful of lenders have launched products under the latest phase of Help to Buy, with NatWest owner RBS, Halifax and Bank of Scotland taking applications from last week.

RBS said the typical applicant so far is 32 years old and looking for a joint mortgage for a property. The youngest to date is 19 years old, with the oldest being 42.

The Government is offering £12 billion worth of guarantees under Help to Buy to encourage lenders to offer mortgages to credit-worthy home buyers with deposits as low as 5%.

RBS and NatWest were the first to offer products under the scheme, including a two-year fee-free fixed rate deal at 4.99%. RBS/NatWest started taking applications on Tuesday.

While the new scheme is expected to spark more competition and widen borrower choice as the major players return to the 5% deposit market, experts have pointed out that the rates on offer so far under Help to Buy are not hugely different from what was already available.

Those other lenders who have confirmed their participation - Barclays, Santander, HSBC, Lloyds Bank, Virgin Money and Aldermore - are expected to give more details about the deals they plan to offer nearer to their launch dates.

Help to Buy has fuelled fears of a housing boom as it comes at a time when house prices in London and the South East in particular have already been rising strongly as demand from potential buyers has been outstripping the supply of homes on the market.