Throughout last year, Kitty Ussher, an up and coming Labour MP, fought a high profile campaign to save the accident and emergency department at the NHS hospital in her Burnley constituency.

It was slated for closure and there were fears among the townspeople that lives could be lost if they had to be taken in an emergency to the hospital in Blackburn.

In June, Ms Ussher led local protesters on a delegation to London to plead their case with Patricia Hewitt, the health secretary. It may not have been too difficult for the 35-year-old MP to gain access to the minister. For three years, while Ms Hewitt was trade and industry secretary, Ms Ussher was her special adviser.

Before the protesters' bus headed back to Burnley, Ms Hewitt said their presentation had been "amazing". But any decision to open or close a hospital unit is made by local trusts and health authorities. There was nothing Ms Hewitt could do to help her colleague, whose 5,778 parliamentary majority at the last election was not impregnable against the passions roused by loss of cherished NHS facilities.

The health secretary could only intervene if local authorities backed a formal complaint. In this case, that required the support of a scrutiny committee of councillors from Lancashire county council and Blackburn with Darwen borough council. If Burnley won the case to keep its A&E, the chances were that Blackburn's rival department would have to close. Since there was no appeal, Ms Hewitt did not have a say in the matter.

In an account that Ms Ussher posted on her website in November, she said: "The issue has been running for over a year now and it is the biggest thing I have worked on since becoming the town's MP. My mailbag has been stuffed with the deep concerns of local people ... I organised a petition against the changes which easily attracted 10,000 signatures."

Another, organised by the trade union Unison, attracted many tens of thousands more. And Ms Ussher secured a parliamentary debate on the subject. This did not, though, stop her being promoted by Tony Blair in October. She was made parliamentary private secretary to Margaret Hodge, trade and industry minister.

Ms Hewitt is understood to regard protests like Ms Ussher's as a legitimate response to a constituency difficulty. The health secretary did not even dream of reprimanding Hazel Blears, the Labour party chair, after she joined a picket line last month to protest at a decision to close the maternity unit at Hope hospital in her Salford constituency.

Ms Ussher remains resolute. Her website declares: "For most of my constituents, it will take longer in an ambulance to get to Blackburn than it currently takes to get to Burnley General. But the fight is not over ... If, as the local managers make these changes, they do anything that compromises patient safety for my constituents, I promise to be back knocking at the door."