Cabinet minister Hazel Blears has defended her decision to take part in a protest over plans to close part of a hospital in her constituency.
Ms Blears plans to make formal representations on the plan
The proposals for Hope Hospital in Salford, Greater Manchester, are part of the controversial NHS shake-up throughout the country.
Ms Blears, Labour chairwoman, said: "My first and foremost job is to represent Salford and the people of the area."
It is rare for a minister to directly oppose government policy.
However, Ms Blears said her actions would not cause embarrassment to the government.
"This is a normal consultation, it has been going on now for two years and quite right and proper, I am a constituency member of Parliament and I have been putting forward the views of the people of Eccles and Salford.''
Ms Blears took part in the demonstration before Christmas outside the hospital over proposals to close and relocate its maternity unit.
Health chiefs want to concentrate maternity services in the region in three centres providing high-quality intensive care for babies.
Ms Blears denied she was panicking about whether or not she would be re-selected as an MP when boundary changes come into force.
''I have been campaigning on health service matters in my constituency for as along as I have been the member of Parliament and before that when I was a local councillor."
The final decision on moving the unit is not due for several months, but her spokesman confirmed that Ms Blears had privately lobbied Health Secretary Patricia Hewitt about the closure, and planned to make formal representations.
He added: "She intends to campaign against it - it is a very hot issue locally."
The government is determined to push ahead with a re-organisation of the NHS, which will see some closures.
It aims to consolidate but improve the services on offer at other hospitals.
Ms Blears' support was considered acceptable by chairman of the health select committee, Labour MP Kevin Barron.
"If we're in the early stages of consultation about the changes in health services in your constituency, I think Hazel's got every right to have a say about what's going off...
"The problems come a few months down the road as it were - where clearly if a final decision has been taken, then I think we'd all be expected to accept the reconfiguration."
Ms Blears's efforts follow Home Secretary John Reid's presence at protests against hospital cuts in his Airdrie and Shotts constituency in April.
Campaign group Health Emergency accused Ms Blears of being hypocritical by opposing local closures while supporting central government policy.
Health Emergency's head of campaigns, Geoff Martin, said Cabinet ministers were only supporting local protests "in a bid to save their own political skins."
"There are 29 hospitals up and down the country facing the immediate threat of cuts and closure to key services in 2007.
"Will Hazel Blears be joining demonstrators on the streets in each of those areas or is this just a classic case of 'not in my back yard'?"
In or out?
Ms Blears' Conservative counterpart Andrew Lansley, who said she needed to consider whose side she was on.
"It is a government policy to say that units must be much larger.
"So if Hazel Blears doesn't like what happens as a consequence of government policy in her constituency, then perhaps she should change the government policy - or get out of the government."
Ms Blears, when asked on BBC's World at One, declined to specify her plans for when John Prescott steps down next year as deputy leader - although she is widely expected to enter the running.