A national postal strike planned for this Thursday and Friday will go ahead. The action, to begin at midnight, is over a row about pay, conditions and Royal Mail's modernisation plans. Dave Ward from the Communication Workers Union said: "What we've seen in the last few days is in our view deliberately choreographed in a way that tells us that the government and Royal Mail are working hand in hand to avoid any chance of us reaching a solution. "The only deal they were prepared to reach was a deal on their terms. We know the strike action, which will now go ahead, is going to damage customers...but we genuinely believe we have no alternative." The decision comes after more than 30 hours of talks between Royal Mail and the Communication Workers' Union (CWU) this week failed to reach an agreement. The prime minister had been urging unions and managers to agree a deal, saying a strike would be "counter-productive". On Thursday, mail centre staff and drivers will strike, while on Friday delivery and collection staff will take action. During Prime Minister's Questions in the Commons, David Cameron accused Mr Brown of "an appalling display of weakness" by apparently dropping plans to reform Royal Mail. The Tory leader said it required "leadership, some backbone and some courage" to prevent union militancy. He urged the Prime Minister to "condemn these strikes and join me in sending a direct message to the trade union to call this strike off". Mr Brown replied: "I said exactly that last week, that it was counter productive for there to be a strike. It's in nobody's interest that this strike goes ahead."