CNN- LONDON, England (Reuters) -- Commonwealth ministers sought on Thursday to ratchet up pressure on Zimbabwe over its controversial land seizures and press for observers to monitor next year's presidential elections.

But diplomats said calls for firm action from Australia, Canada and Britain -- which says the EU may act too -- were likely to be tempered by caution from African ministers seeking to avoid confrontation with Harare.

Members of the organisation's democracy watchdog, the eight-strong Commonwealth Ministerial Action Group (CMAG), were discussing whether to put Zimbabwe formally on their agenda -- a first step towards possible suspension from the Commonwealth.

Australia, which hosts a Commonwealth summit in March, has said CMAG should put Zimbabwe squarely in its sights and consider suspending it from the 54-nation group, largely made up of former British colonies.

Britain, Zimbabwe's former colonial ruler, accused President Robert Mugabe on Thursday of wreaking "astonishing" damage on the economies of southern Africa by failing to halt the violent occupations of white-owned farms in his country.

Both Britain and Australia have condemned the breakdown of law and order in Zimbabwe and what they say is intimidation of the opposition, media and judiciary by Mugabe's supporters.

Unless there is change in Zimbabwe soon the European Union is likely to take "very tough measures" next month, British Foreign Secretary Jack Straw told BBC radio.

Although CMAG has repeatedly expressed concern at events in Zimbabwe, it has never officially put the country on its agenda -- confining its actions to nations where clear constitutional violations such as military coups have taken place.

Commonwealth officials said CMAG could discuss issuing a warning to Zimbabwe of possible "smart" sanctions on senior officials if the violence continued.

But Zimbabwe's neighbours in the 14-nation Southern African Development Community (SADC) repeated their opposition to any sanctions this week, insisting violence had subsided and Mugabe -- who has ruled his country since independence from Britain in 1980 -- was committed to free and fair elections.

SADC members say they oppose a confrontational approach to Zimbabwe's most divisive problem -- redistributing to landless blacks large swathes of farmland owned by whites.