Markets call for Opec action

As Libyan oil production ceases and crude prices reach nearly $120 a barrel, Amrita Sen, an analyst at Barclays Capital, says it is essential that Opec, the oil producers' cartel, moves beyond words and takes affirmative action to increase supplies. She talks to Jack Farchy, commodities correspondent, about Saudi Arabia's pivotal role and the likely repercussions of further political upheaval in the Middle East.