Health Secretary Andrew Lansley said: "These women are the victims of a fraudulent company and I know this situation is causing a huge amount of anxiety. I want to reassure those affected by the news today that they will be provided with all the help they need from the NHS."
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"I definitely get less money than a male in my situation would," she said. "Definitely."
Muscular Dystrophy UK said the lack of an option to label abusive tweets based on disability was preventing more reporting.
The Labour leader will say Britain's "distorted" economy cannot be rebalanced without taking on the power of the financial sector.