Recent rate rises and the passing of the Stamp Duty exemption have done little to slow demand, according to the latest National Mortgage Index from Mortgage Advice Bureau (MAB).

The report, which uses data from over than 300 brokers and 700 estate agents across the UK, found that the number of mortgage applications has increased again in March 2012.

Boosted by worries over further increases to lenders’ SVRs and the withdrawal of upfront discounted deals, mortgage applications are up 98.1% from December 2011 and 5% higher than the same time last year.

Meanwhile, the number of borrowers choosing fixed-rate deals increased to 78.7% in March from 73.3% in February. This is the highest level in the last 12 months and the second highest level since the summer of 2009.

Brian Murphy, head of lending at Mortgage Advice Bureau, said: “Demand remains strong and it has been a strong first quarter for mortgage activity. Despite rising rates and the end of the stamp duty holiday in March