Foreign ministers will debate whether Pakistan should be suspended from the Commonwealth over President Pervez Musharraf's declaration of emergency rule at an extraordinary meeting Monday.
Nations including Britain and Canada have called for tough action ahead of the Commonwealth Ministerial Action Group gathering and Secretary-General Don McKinnon described the state of emergency as a "step in the wrong direction".
Foreign ministers from Britain, Canada, Lesotho, Malaysia, Malta, Papua New Guinea, Saint Lucia, Sri Lanka and Tanzania will meet in London to discuss whether the state of emergency breaches Commonwealth principles.
Musharraf imposed emergency rule on November 3, suspending the constitution, sacking the chief justice and imposing restrictions on the media days before the Supreme Court was to rule on the validity of his October election victory.
Before these moves, powerful Commonwealth nations were talking tough about potential action against Pakistan.
British Foreign Secretary David Miliband told the House of Commons Wednesday that suspension was "one of the tools that is available" to the Commonwealth and urged Musharraf to honour a pledge to step down as army chief.
Canadian Foreign Minister Maxime Bernier said that the country is "pressing for a strong Commonwealth response that sets clear deadlines for the end of the state of emergency and for the restoration of democratic processes".
Pakistan was suspended from the Commonwealth - a 53-nation group dominated by former British colonies - in 1999 after Musharraf seized power in a coup backed by the army.
But it was restored as a full member five years later in 2004 after Musharraf promised to give up his dual role as president and military chief by the end of the year.
Monday's meeting in London is likely to act as a curtain raiser for the Commonwealth Heads of Government Meeting in Kampala, Uganda, on November 23 to 25.
McKinnon has refused to preempt the outcome of Monday's meeting, saying ministers were "clearly very concerned" about Musharraf's actions. "These are nine quite independent foreign ministers. If you look where they come from, they could quite easily have nine different views," he added.
The Commonwealth Human Rights Initiative (CHRI), the grouping's main rights group, underlined the importance of sending a strong message to Pakistan.
"This is a moment of singular importance for the Commonwealth to recognise that democracy, democratic processes and institutions, the rule of law and just and honest government are the fundamental political values of the Commonwealth.
"Swift action will reinforce that membership of the Commonwealth is predicated on an absolute promise to protect and promote these values," it added in a statement. The group added Pakistan's attendance at the Commonwealth summit in Uganda would be "inappropriate."