Brown's Baroness emerges from the shadows

Baroness Cathy Ashton is one of the lowest-profile ministers to have served in Gordon Brown's Cabinet. But she has impressed observers since moving to Brussels last year to replace Peter Mandelson as Trade Commissioner.

Her appointment as the EU High Commissioner would satisfy calls for a woman to hold one of the EU's two top jobs.

"We have to have a woman on board," said one EU diplomat. "And there's a growing consensus that we can't have a stronger European foreign policy without having the British in pole position. It would be like having created the Euro without the German Deutschmark."

Baroness Ashton worked in the public sector before switching to politics. She was director of Business in the Community, working with business to tackle inequality, chaired Hertfordshire health authority and became a vice-president of the National Council for One Parent Families.

Tony Blair gave her a life peerage in 1999 and appointed her to the Government as an education minister in 2001. She won plaudits for her expertise in the brief. Four years later she was voted House Magazine Minister of the Year.

In 2006, she quit as farms minister after just a week, when it emerged that No 10 had accidentally double-booked her. She had wrongly assumed she would be giving up her post at the Department for Constitutional Affairs to take the job.

When Gordon Brown became Prime Minister he promoted her to the Cabinet as Leader of the Lords.

A year later she moved to Brussels when Lord Mandelson returned to the UK political frontline.

As High Commissioner, she would head the EU's new External Action Service, a beefed-up foreign ministry created by the Lisbon Treaty. The ministry will comprise 5,000 diplomatic staff posted to around 130 EU embassies around the world.

Her chief rival for the post could turn out to be David Miliband, the Foreign Secretary. He has denied any interest but his name is often mentioned in EU diplomatic circles.