A key aide to Bob Ainsworth, the UK defence secretary, has resigned and criticised the UK's mission in Afghanistan.
Eric Joyce, the now former parliamentary private secretary to Ainsworth, vacated his post on Thursday and said that there were "problems" with the handling of the war that needed "fixing with the greatest urgency".
"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," he said in a resignation letter.
"I think we must be much more direct about the reality that we do punch a long way above our weight, that many of our allies do far too little, and that leaving the field to the United States would mean the end of Nato as a meaningful proposition," the former army major and legislator said.
He added that it was believed that within Nato, "Britain fights; Germany pays, France calculates; Italy avoids".
In a statement Ainsworth refuted Joyce's comments, saying that the war in Afghanistan was key to the UK's security.
"We will not walk away from that responsibility," Ainsworth said.
"The picture he paints is not one that I nor many people within the MoD [Ministry of Defence] recognise, whether military or civilian."
Last month the UK suffered its 200th troop death in Afghanistan since 2001.
Questions have in turn been raised about the suitability of the UK mission and whether it has adequate resources.
There are currently about 9,000 troops in Afghanistan.
The UK entered the country in 2001 in support of the US to remove the Taliban, who were viewed as harbouring al-Qaeda operatives, from power.