Defence cuts threaten ability to run concurrent campaigns, M

Britain would struggle to conduct another campaign like the one carried out in Libya and still sustain its other military commitments because of the impact of sweeping defence cuts, a parliamentary report has warned.

The government also failed to reconcile the "apparent conflict between the military and political objectives" in Libya – whether the aim was to protect Libyan civilians or to remove Muammar Gaddafi from power – and needs to be much more transparent about how it calculates the cost of such operations, MPs say.

The report from the defence select committee released on Wednesday praises Britain's involvement in the Operation Ellamy campaign in Libya, but raises several concerns. They include Nato's reliance on the US and the Royal Navy being forced to halt routine tasks to concentrate on the operation in the Mediterranean.

MPs argue that the Libya campaign took place before most of the cuts demanded by the strategic defence and security review. They say ministers need to revise their assessments of whether Britain could undertake a similar campaign.

"We believe the government will face significantly greater challenges should an operation of similar size be necessary in the future and it will need to be prepared for some difficult decisions on prioritisation," the report says. "We consider that Operation Ellamy raises important questions as to the extent of the UK's national contingent capability. We urge the government to review the UK's capacity to respond to concurrent threats. This work should be conducted as a matter of urgency before the next strategic defence and security review."

The 100-page report singles out pressure on the Royal Navy and highlights how important tasks, such as counter-drugs operations, "were not able to be carried out due to meeting the Libya commitment". And it pointed out that the US provided critical equipment, such as refuelling aircraft and unmanned drones, as well as intelligence. This may not be available in the future, the report says.

MPs also highlighted confusion over the interpretation of the UN resolution, which allowed for the protection of civilians, but not for the removal of Gaddafi. "Although it is difficult to see how the mission could have been successfully completed without [his] losing power, we are concerned that this, rather than the protection of civilians … came to be seen by some countries as an integral part of the mission. The apparent conflict between the military and political objectives meant that the government failed to ensure that its communication strategy was effective in setting out the aims of the operation.

"In future, the government's communication strategy needs to be more effective so that the public are confident of the aims and goals of such operations."

The report urges ministers to provide an estimate of the number of civilian casualties caused by all those involved in the fighting – Nato forces, those under the command of the National Transitional Council, and pro-Gaddafi troops.

James Arbuthnot, the committee chairman, said: "The mission in Libya was successful … the real test is whether the success of this mission was a one-off or whether the lessons it has highlighted mean future missions can be successfully undertaken."

Philip Hammond, the defence secretary, insisted Britain could continue to juggle all its commitments despite the multibillion-pound black hole in the defence budget. "We retain the capability to project power abroad and meet our Nato obligations," he said.

Jim Murphy, Labour's shadow defence secretary, said the cuts had downgraded Britain's military flexibility. "As global uncertainty grows, daily threats are becoming harder to tackle and Britain may no longer be able to perform such a leading military role in the world."