Deputy Prime Minister Nick Clegg has said it is a "real shame" that thousands of public sector workers across the UK are on strike.Mr Clegg said he had a "lot of sympathy for people who are facing disruption", but felt the country wanted the government and unions to "get round the table and sort this out".He added that public sector pensions needed to be reformed in a "reasoned and reasonable way".Picket lines have been set up as the Public and Commercial Services Union (PCS) and three teaching unions protest at planned changes to their pensions.