Swiss groups opposed to war in Iraq have announced a mass demonstration for February 15.
The move is in line with anti-war groups across Europe, who will also be demonstrating on that day.
The Swiss groups, which include political parties such as the Social Democrats and the Greens, as well as trades unions and aid organisations such as Heks and Caritas, expect several thousand people to take part in the demonstration.
Announcing the planned protest, Swiss Coalition, an umbrella group of aid organisations, warned that an attack on Iraq would cause a humanitarian catastrophe.
Jürg Krummenacher, head of Swiss Coalition, said that UN agencies were predicting that half a million Iraqis would be wounded, and five million would become refugees, should war break out.
"It's really quite extraordinary that so many Swiss humanitarian aid agencies are joining together in such a protest action," Krummenacher told swissinfo.
"But we think the situation in the Middle East is very dramatic and very dangerous and that is why we support this demonstration."
"As aid agencies, we do not see ourselves as repair workers, who try to ease suffering during a humanitarian catastrophe because the politicians have failed to prevent it," he said.
"Instead, aid agencies want to play a role in supporting peace and development."
The anti-war movement is also calling on the Swiss government to take a clear stand in the United Nations against a war on Iraq.
"There is absolutely no justification for war whatsoever," said Christian Brunner, president of the Social Democrats.
"Of course our party has no wish to defend the regime of Saddam Hussein, but the push for war has completely blocked any search for a political solution in the region."
"We think the Swiss government should remain firm on the demand that war is only possible if the UN Security Council agrees," agreed Krummenacher.
"And even then I think our government should oppose it, because a war would destabilise the whole region. Even if Saddam Hussein could be ousted we see no [potential] for the country in such a situation - there would be no possibility of democratisation."
Rita Schiavi, vice-president of the Swiss Trades Unions Association, said a war against Iraq would be not only a humanitarian and political catastrophe but would also cause widespread social and economic damage.
The anti-war groups do not support the argument that Saddam Hussein's brutal dictatorship alone is a justification for an attack.
"We have to see that it is not only the Iraqi population that suffers under a dictatorship, other peoples are ruled by dictators, too" said Krummenacher.
"For us this is no reason for a war on Iraq. We have been working in the ground in Iraq for ten years, and we have seen that the sanctions have served only to support Saddam Hussein.
"The only way out would be to give up the embargo and try together with Iraqi politicians to start a democratisation process in the country."
The planned demonstration reflects growing concern across Europe at the apparent inevitability of war.
Despite an open letter signed by eight European leaders calling for support for the position of the United States, opinion polls indicate that most Europeans remain strongly opposed to an attack on Iraq.
For Krummenacher, protest is the last resort.
"If there are a lot of demonstrations, not only in Europe but also in the United States, and if hundreds of thousands go out to demonstrate against this war, then maybe we can succeed in getting the European governments to try to convince the US that a war is not the right solution."
On February 15, anti-war demonstrations are planned in Europe's capital cities.
Over 90 Swiss aid organisations, trades unions and political parties support the anti-war demonstration.
This week, eight European prime ministers signed an open letter calling for support for the United States, but opinion polls suggest that most Europeans remain opposed to war.
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