Spanish Prime Minister Jose Luis Rodriguez Zapatero has been heckled by the public on national day, in what has been interpreted as a sign of his falling popularity.With the recession hitting hard and unemployment soaring the Socialist government has come under mounting criticism over its handling of the economy. Sections of the crowd whistled and shouted “resign!.” But talking to Madrid officials Zapatero tried to make light of the noisy reception, saying it happened every year. Those heckling were said to be mainly supporters of the opposition conservatives. The government is also under pressure over its participation in the war in Afghanistan. The defence minister said she believed the new strategy of the Obama administration would address Spanish concerns about the mission. An opinion poll published in one leading newspaper today shows the centre-right on 43 percent against 38 percent for the socialists.