She is the first woman to run the country since a tearful Margaret Thatcher departed Downing Street in November, 1990.

Yet No 10 became engaged in linguistic gymnastics yesterday to try not to confirm that Harriet Harman, Leader of the Commons and deputy Labour leader, was in fact running Whitehall while Gordon Brown and family enjoy a break on the Suffolk seaside.

"Downing Street is operating in the normal way," insisted the Prime Minister's spokesman.

There had apparently been an early-morning meeting in Downing Street but he was not going to comment on "internal processes".

Was Ms Harman not chairing the meeting, the spokesman was asked? "While the Prime Minister is on holiday, senior ministers are available to deal with the day-to-day government business. Harriet Harman is one of those," came the reply.

So who is in charge, the spokesman was asked? "The Prime Minister is in charge while he is on holiday." The official admitted that Ms Harman had "held meetings in Downing Street this morning". Held? "She has been in meetings this morning."

So she has no special role then? "She is a senior minister. The PM remains in charge."

However, when later confronted, Ms Harman insisted she was indeed "minding the shop this week".

Back at No 10, the spokesman relented: "She is the minister who is co-ordinating government business this week."

It is thought, without a Deputy Prime Minister, Chancellor Alistair Darling and Lord Chancellor Jack Straw will deputise in subsequent weeks this month.

It has already been suggested that, in anticipation of her new role, Ms Harman produced a list of demands of No 10, including late-night briefings on the next day's headlines, a daily 7.30am conference call followed by a 9am meeting around the Cabinet table.

By sheer coincidence yesterday morning, Ms Harman popped up on television to declare that the best was yet to come from Gordon Brown. She said: "He is the solution, not the problem."

Today, in her role as Minister for Women, Ms Harman published a new report "Women's Changing Lives", which charts progress made on the UK Government's priorities for women.

The report coincides with the UK Government's announcement of new laws on homicide for England and Wales, which will end the provocation defence in cases of domestic homicide where the husband escapes murder charge by blaming his wife for "provoking" him by her infidelity.