MPs have called on the government to do more to fight the growing Aids epidemic across the world.

A cross-party group of MPs used a Westminster Hall debate on Wednesday to urge action on a range of issues including helping third world countries and lobbying the US government to change its policies.

The debate, led by Labour backbencher Mark Lazarowicz, highlighted the scale of problems the disease is now causing. Aids-related deaths are part of the reason why there is famine in sub-Saharan Africa, he said.

Conservative shadow international development minister Robert Key said it was vital that Western governments were not judgemental about the spread of Aids in developing countries.

"It is a temptation we should resist," he said before criticising the US government's decision to cut funding to family planning programmes run by the UN.

"Does [president Bush] understand the consequences of his policy?" he asked.

For the Liberal Democrats, international development spokesman Jenny Tongue said it was vital that work to find a vaccine for the disease was not forgotten.

"If ever there was a weapon of mass destruction, Aids is it," she said.

"It's an absolutely horrific scenario that people face across the word."

Tongue argued that the disease would not be combated simply by forcing drug companies to provide cheaper medicine.

Better nutrition for millions of people across the world was another factor.

She also called for more action to cut the debts of Third World countries, which sees African countries spend £14 billion-a-year on debt repayment.

Tongue urged ministers to use whatever leverage they had with president Bush's administration to reverse cuts to the UN family planning programmes.

"We have this wonderful special relationship with the US. For goodness sake, what return are we getting for it?" she asked.

Replying for the government, Foreign Office minister Bill Rammell said the disease was now the biggest single problem for developing countries.

"This is an important debate. The scourge of Aids is reversing the development gains of the last few years," he said.

The government would have spent £1 billion by 2006 on Aids prevention programmes around the world and that there was some cause for optimism as some countries that had begun contraception programmes, such as Senegal, were making progress, Rammell said.

"There is evidence that Aids can be beaten. We are not complacent but we do believe that through the action we are taking...we are making a significant contribution."