The US will no longer be able to stockpile cluster bombs at its military bases in Britain under government proposals for an international ban on the controversial weapons, it emerged last night.

As diplomats from more than 100 states unanimously passed a treaty banning the use of cluster bombs around the world, it emerged that British ministers are prepared to go further.

The government has agreed to scrap the two types of cluster weapon in the armoury of British forces, but it will also ask the US to get rid of its cluster bombs based here, and it will no longer ask for a "phasing out" period for its newest cluster munition - the M73, which is attached to Apache attack helicopters.

Both this weapon and the M85 - an Israeli-designed artillery shell used by British forces during the 2003 invasion of southern Iraq - will now be scrapped as soon as possible.

Cluster weapons scatter "bomblets" across a wide area. Many of them fail to explode, later killing and maiming civilians long after the weapons are fired.

Gordon Brown yesterday described the treaty - due to be formally signed in Oslo in December - as "a major breakthrough". He added: "We will now work to encourage the widest possible international support for the new convention."

In a statement released by Downing Street, he said: "I am delighted that the negotiations in Dublin have come to a successful conclusion, and congratulate the Irish government and all those involved.

"I am confident that this agreement is in line with British interests and values, and makes the world a safer place."

Final negotiations centred on the issue of "interoperability" - how far troops from countries signed up to the treaty should "cooperate" with troops from countries that have not, notably the US.

The US claimed last week that the treaty could jeopardise its participation in joint peacekeeping and disaster relief operations, as most American military units have cluster bombs in their armoury.

The US is not party to the Dublin talks, but officials in London emphasised yesterday that it was the government's intention to ban cluster bombs at American bases in Britain.

Troops from Britain and other countries signing up to the cluster bomb ban would not be subjected to prosecution under international law if they were engaged in operations with those still free to use the weapons, the draft Dublin treaty is expected to say.

The Ministry of Defence was reluctant to abandon the UK's two cluster weapons, though some defence officials said yesterday that they were hardly going to be useful against small groups of Iraqi insurgents or Taliban fighters or in the battle for "hearts and minds".

Campaigners and human rights groups welcomed the UK government's ban on cluster weapons.

"The treaty will create a new international standard that will prevent the use of cluster munitions even by those countries that have not signed up," said Simon Conway, of Landmine Action UK.

Along with the US, Russia, China, Israel, India and Pakistan are not taking part in the Dublin talks.