Her office, which manages immigration, counterterrorism, policing and anti-drug policies, has not yet commented on reports of her resignation.
The reports come days before Gordon Brown, Britain's prime minister, is expected to reshuffle his cabinet in the run-up to next year's general election.
They also come two days before local and European Parliament elections are due to be held, in which Britain's ruling Labour Party is expected to suffer a massive drop in support.
However, all major parties in the country appear to have lost support over the expenses scandal.
More than a dozen members of parliament have been forced to announce they will be stepping down since the reports were first leaked a month ago.
Many Britons are furious that many members of parliament have milked the expenses system, claiming from taxpayers the cost of everything from dog food to cleaning their swimming pools at a time when many people are struggling in a recession.