Former CIA agent Valerie Plame has launched a civil suit against US Vice President Dick Cheney and his former aide Lewis Libby.

The suit also names President George W Bush's chief political adviser, Karl Rove, and claims Ms Plame's constitutional rights were violated.

When her identity was leaked in a newspaper column her husband, US Ambassador Joseph Wilson, blamed it on officials in the Bush administration.

He said they wished to discredit him for contesting White House claims that Iraq had sought to acquire uranium from the African country of Niger.

After a lengthy special investigation, Lewis Libby, the former chief of staff to Vice-President Dick Cheney, was charged last October with perjury and obstructing the work of the Special Prosecutor.

Now Ms Plame and her husband have filed a civil lawsuit against Dick Cheney, Lewis Libby and Mr Rove.

The special investigation has not yet found that her identity was intentionally leaked by anyone.

But the couple's civil suit will lead to a repeat of the debate over the intelligence used to justify the invasion of Iraq.