Labour will refer high street banks to the competition authorities if it is elected in 2015, Ed Miliband, the Labour leader, is expected to say in a speech on Friday.
The UK's headline rate of inflation fell to 2% in December, meeting the government-set target for the first time since November 2009, official figures show.
The Bank of England's Monetary Policy Committee has left interest rates unchanged again at 0.5%.
The Bank of England (BoE) could lower the unemployment target it has said must be reached before it raises interest rates, according to some experts, as jobless figures fall faster than expected.
Bank of England governor Mark Carney has warned on the complications of withdrawing monetary stimulus - just hours before the US Federal Reserve may announce a tapering of its own asset purchase programme.
The Bank of England has maintained interest rates at 0.5% and the size of the asset purchase programme at £375bn.
The mortgage aspect of the Funding for Lending Scheme (FLS) is to be discontinued in light of improved market conditions.