A few days before Christmas, while Britain shivered beneath freezing fog, Hazel Blears donned a thick woollen overcoat and set off on foot for her local hospital. Those who spotted the familiar figure of their MP walking briskly towards the building probably assumed it was just another routine photo opportunity for a cabinet minister anxious to convey her support to National Health Service staff and patients.

Instead, the chairwoman of the Labour party headed resolutely for a throng of angry mothers gathered outside the hospital in Salford and joined a very visible public protest against the proposed closure of its maternity unit.

Not exactly the festive gift that Patricia Hewitt, the health secretary, might have hoped for from a cabinet colleague, but then Blears — whose dedication to “connecting” with her local community led her to spend a day last summer stacking shelves in Tesco — is nothing if not ballsy.

She may be little bigger than an Oompa-Loompa (she is less than 5ft tall) but what she lacks in physical stature she more than makes up for in chutzpah. “I am absolutely sure joining the protest was the right thing to do,” she says. “It is right and proper that as an MP you put forward your constituents’ views. Otherwise, constituents whose MP happens to be a government minister are effectively disenfranchised.”

Perhaps so. But the spectre of a senior Labour politician — especially one whose job is to promote party unity — publicly demonstrating against government policy was guaranteed to cause a furore.

Blears — expected to run for the deputy leadership of the Labour party — has backed some of the very policies that have led to the proposed closure of Hope hospital’s maternity unit.

How does she square this with protesting when it hits her own back yard? As one former cabinet minister put it: “You can’t have it both ways. You are either a constituency MP first and foremost, or you recognise that as a member of the government, your government responsibilities come first.”

Accusations of hypocrisy rained down but Blears stuck to her guns. “Part of my political personality is that I do take it on the chin,” she says.

The 50-year-old former Home Office minister has spent almost her entire Christmas “break” charging around Salford campaigning for the Labour party. So far this holiday there has been just one full day off — Christmas Day — when she and her husband Michael, a lawyer, played host to her parents at their semi-detached home in Salford.

“Mum and dad came over and I did the cooking. There is a point in your life when you stop going to your parents for Christmas and they start coming to you. I think it’s quite nice for them.”

Other than that, aides recall just one half-day off this month when she hit the boutiques of Marylebone High Street, central London, to select “beautiful” presents for staff, friends and family.

There was a time when she was so fiercely loyal and enthusiastic about every government initiative that she threatened to out-Blair Tony Blair. These days she can no longer afford to champion the government line unquestioningly when confronted with constituents’ gripes.

Earlier this month she discovered that she was facing a bitter and unexpected fight to hold on to her seat, as a result of boundary changes merging the three seats of Salford, Eccles and Worsley into two.