Bradford & Bingley has raised its mortgage rates by as much as 0.55% for new borrowers.
The Treasury is searching for an independent valuer to assess any compensation due to Northern Rock's former shareholders.
House prices fell 2.4% in May, according to the Halifax, providing further evidence that the UK housing boom is over.
Interest rates are expected to remain at 5%, according to analysts, as the Monetary Policy Committee (MPC) prepares to announce its latest decision.
Investors should exercise caution over the coming months as the UK is far more likely to suffer a recession than it was in 2001, according to James Carrick, investment strategist at Legal & General Investment Management (LGIM).
The Bank of England's Monetary Policy Committee (MPC) voted 8-1 to keep interest rates held at 5%, according to minutes released today.
Arrears at Northern Rock have increased due to a squeeze on the availability of mortgages in recent months.
Northern Rock's shareholders have begun a legal challenge against the Government to receive compensation for the shares lost when the bank was nationalised.
The Bank of England's Monetary Policy Committee (MPC) has decided to keep interest rates at 5%.
Halifax says house prices fell by 0.9% in the twelve months to April, providing further evidence the housing market is in decline.