"The threats of the former British prime minister are worthless to the Iranian nation," Mehman-Parast said on Saturday, adding that Blair is not in a position to make such comments about the Islamic Republic of Iran.
He called on Blair to speak about his country's wrong policies during his premiership instead of uttering interfering remarks on the other countries.
The spokesman said Blair should also account for the crimes committed by the British forces during the war in Afghanistan and other parts of the world.
His comments came after Tony Blair in an interview with the Times newspaper backed "regime change" in Iran and Syria.
Blair's comments came as hundreds of demonstrators still clash with police in different rallies in Britain, despite a government ban on marches imposed after growing protests rocked the country in August.
Unrests erupted in London and several other English cities in August and left, at least, five people dead, and the government has been on high alert ever since.
Unrest has rocked Britain on a scale unprecedented in 30 years following the police's killing of black male Mark Duggan in a shooting spree in the London suburb of Tottenham on August 4.
Tension erupted on August 6, when a few hundred people gathered outside a police station in Tottenham to protest the killing.
The protests later spread to major cities like Birmingham, Liverpool, and Bristol.
British Prime Minister David Cameron later threatened to call in the army if protests persisted, and analysts believe that his threat displayed that the White Hall's claim about being an advocate of human rights and freedom of expression was nothing but an empty, boastful remark.
Meantime, British courts are accused of yielding to the government pressures, with judges and magistrates handing out unduly harsh sentences to the young people involved in the recent unrests after being reportedly advised to "tear up" normal sentencing guidelines when dealing with convicted protestors.
MPs and rights activists have expressed deep concern over "naming and shaming" of young protestors and giving them long sentences as part of the Conservative-led coalition's crackdown on protestors.