Energy policy and supply have continued to dominate leaders' exchanges at prime minister's questions.

The question session was held on 30 October 2013, the day after executives from the six largest energy companies in the UK gave evidence to the Energy and Climate Change Committee.

Labour Leader Ed Miliband began by saying: "Most energy companies don't want a price freeze. Most consumers do - that's why energy companies are against a price freeze.

"You're so on the side of the energy companies, we should call them the "big seven" - the prime minister and the big six energy companies."

The prime minister replied: "Who was it gave us the big six? Yes, when Labour first looked at this there were almost 20 companies but because of your stewardship we ended up with six players.

"You talk about a price freeze but down the corridor, they [Labour] have been voting for a price rise - that is right. They voted for a decarbonisation target that everyone accepts would rise prices. If you want a price freeze, why have you just voted for a price rise?"

Mr Cameron was referring to the progress of the Energy Bill in the House of Lords, where Labour voted in support of a cross-party amendment aimed at requiring the government to set a decarbonisation target in 2014. The amendment was defeated.

Mr Miliband accused him of being "too weak to stand up to the energy companies", but Mr Cameron responded that he was "too weak to stand up to Len McCluskey, who tried to wreck Scotland's petrochemical industry".

"Where, frankly, we have a real problem with a rogue trade unionist at Grangemouth who nearly bought the Scottish petrochemical industry to its knees we need to have a proper inquiry - a Labour inquiry," the prime minister stated.

Unite official Stephen Deans - who represented workers in a dispute over the future of the Grangemouth oil refinery - resigned days after an agreement was reached to keep the plant open.

Before his resignation, Mr Deans had been suspended while Ineos investigated his involvement in the row over the selection of a Labour candidate in the Falkirk constituency.

You can watch a statement on Grangemouth in the Scottish Parliament here.