An aide to Britain's defense minister resigned Thursday, criticizing the government's handling of the conflict in Afghanistan and calling on Britain to scale back its commitment there.

The resignation is particularly embarrassing because Eric Joyce, a former army major, is one of the few top-ranking members of the governing Labour Party with any military experience.

In a resignation letter addressed to Prime Minister Gordon Brown and published by Channel 4 News, Joyce called on Brown to publicly state when Britain would begin removing its forces from Afghanistan and to do a better job of justifying the war to voters.

"I do not think the public will accept for much longer that our losses can be justified by simply referring to the risk of greater terrorism on our streets," the letter said. "We also need to make it clear that our commitment in Afghanistan is high but time limited."

Joyce also launched a stinging attack on Britain's NATO allies, saying that many "do far too little." In an editorial published on Channel 4's Web site, Joyce also argued that Britain needed to get more out of the United States.

"President (Barack) Obama needs to show in practical ways his appreciation of our effort," he wrote. "For many, it seems that Britain fights; Germany pays; France calculates; Italy avoids. If the United States is seen as valuing each of these approaches equally then I think they may will end up shouldering the burden themselves, with the destruction of NATO's credibility that would bring with it."

Joyce served as Parliamentary Private Secretary to Defense Secretary Bob Ainsworth — an unpaid post typically reserved for ambitious lawmakers loyal to the party leadership. In a statement, Ainsworth said he was grateful for Joyce's service but that "the picture he paints is not one that I nor many people within the Ministry of Defense recognize, whether military or civilian."

"Everyone in defense, and the wider government, is fully committed to ensuring that our forces succeed in the operations on which they are engaged in Afghanistan."

Brown's government is under increasing pressure over his handling of the war in Afghanistan, which has claimed 212 British lives — including two fatalities announced Thursday. Opposition politicians, retired military leaders, and even serving members of the government have criticized Brown for allegedly failing to provide enough support to soldiers in the field.

In another uncomfortable moment for the government earlier this summer, outgoing British minister Mark Malloch-Brown said that forces in Afghanistan needed more helicopters — directly contradicting the prime minister, who insisted the military had all that it needed.

Support for the war is slipping, with critics — including lawmakers on Britain's influential Foreign Affairs Committee — calling the mission too open-ended and its goals too vague. At various times British officials have emphasized the need to make Afghanistan a stable democracy, to curb the opium trade and to stop al-Qaida and related groups basing themselves there.