Tony Blair and Iain Duncan Smith have clashed over healthcare provision for the elderly.

The Tory leader challenged the prime minister over the number of care home places in Britain, claiming that provision had plummeted due to "expensive rules and regulations".

"Since the prime minister came to power more than 50,000 care home beds have closed. Does he think it's anything to do with his policies?," he demanded.

Blair responded by pledging to MPs that the government would spend £1.4 billion towards helping the elderly in care facilities and their own homes.

"That money was opposed by the right honourable gentleman," he said, asking the Conservative leader how he would increase provision and improve standards of care. "That is money we are putting into the system. It is money that he is opposed to."

The Tories, he claimed, were attacking rules intended to improve conditions for care staff and guarantee tough standards of care.

"If he is opposed to the Care Standards Act, let him stand up and say so now," he said.

Duncan Smith accused the government of presiding over a care crisis that was impacting on the NHS, with bed-blocking and delayed discharges causing delays and bottlenecks in hospitals.

"That is not health care, that is Kafka care - the people who will suffer are the most vulnerable in society.''

Liberal Democrat leader Charles Kennedy challenged the government over the deployment of more troops in Afghanistan. He argued that having peace keepers on the streets of Kabul and troops fighting in the mountains was a recipe for disaster that the chief of defence staff had warned against.

"Why is it that we're combining both roles when the Americans don't wish to?" he asked.

Blair replied there was fully support from the army for the widening of British involvement.

"Some of what has been reported is not in accordance with the facts. There was always going to be a period when we had to mop up the last remnants of Taliban and al Qaeda forces," he said. "It's important we get the job done fully. I do not believe there is any mismatch."

Duncan Smith then challenged the prime minister over the issue of the sovereignty of Gibraltar and a pledge by Blair that the people that live on the Rock would have the final say over their future.

"Given 80 per cent of the population turned out to oppose the proposals, does he still stand by his words?" he asked.

Blair retorted that the negotiations with Spain had been started by the Conservatives.

"This is a process that began under the last Conservative government. This total opportunism of the Conservatives has to be exposed. This process was set up for a very good reason. The present arrangements between Spain and Gibraltar suit nobody."

Labour backbencher Mark Lazarowicz asked what further steps the prime minister would like to see the Commonwealth taking on Zimbabwe.

Blair said he very much welcomed the Commonwealth's decision to suspend Zimbabwe and paid tribute to the troika that announced the decision on Tuesday.

"This has been a difficult issue for them and the circumstances in which they find themselves but I think it was the right decision to take. It sends out a very clear message that Africa will not compromise on the issue of democracy," he said.

Another Labour backbencher Tony McWalter had previously stunned the prime minister by quizzing him on the philosophy of his government. He asked what part of the prime minister's philosophy would be used on reforming the House of Lords.

Blair, referring to his mangled reply at their last encounter, said he would resist "revisiting the scene of earlier triumphs".

"In respect to the House of Lords there is a consultation process, we are listening to that consultation," he said.

Blair accepted there was opposition to his plans from his own benches but claimed Conservative peers were equally opposed to Duncan Smith's plans.

"I think we've all got to do a little homework on this. I would like to see it remain as a revising chamber but I would not like to see it competing with the House of Commons."