Iranian president Mahmoud Ahmadinejad has begun the campaign for June's presidential election with a defiant speech against Iran's enemies.

Addressing a rally in the south of the capital, Tehran, President Ahmadinejad appealed to Iranian
patriotism.

He compared Iran's enemies to "dogs", saying: "If you retreat, they attack; if you attack, they retreat."

Ahmadinejad's main opponent, Mir-Hossein Mousavi, has attacked the president's handling of the economy.

Already, on the first day of campaigning, the battle lines have been clearly drawn.

In contrast to Ahmadinejad's defiant speech, Mousavi used a television appearance to criticise the government for producing high inflation and high unemployment.

Mousavi was due to speak at a major rally in Tehran's main football stadium last night in an attempt to inspire a revival of the fervour that swept reformists to power in 1997.

The biggest challenge for those trying to unseat President Ahmadinejad is to overcome apathy and a widespread disillusionment with the political system.

The lower the turnout, the more likely Ahmadinejad is to remain in power.