The first televised debate ahead of Afghanistan's presidential poll has been held - without Hamid Karzai, the country's president.

Karzai, widely seen as the front runner in the August 20 election, pulled out less than 24 hours before the debate took place on the country's most popular television network on Thursday.

An empty podium marked his absence while his policies were criticised by two of his biggest challengers, Abdullah Abdullah, the former foreign minister, and Ashraf Ghani, the former finance minister.

The Karzai team said he had not been given enough notice for the debate on private TV channel Tolo, which they accused of being "59 per cent against Hamid Karzai".

Karzai's campaign also said the president did not want to take part because all the country's 41 presidential candidates were not invited.

'Broken promise'

Ghani, also a former senior World Bank official, has repeatedly asked Karzai to debate with him.

"It is the Afghan public that will suffer another broken promise ... if the future plans of each candidate is not made clear standing side-by-side his or her rival," Ghani said on his website earlier this week.

Jahid Mohseni, the chief executive of Moby Group, which owns the Persian-language Tolo TV, said the station hoped to hold a series of three debates and that Karzai was welcome to join the remaining two.

Mohseni said negotiations over Thursday's debate began more than three weeks beforehand.

He said: "Afghanistan's obviously a new democracy and we've got a lot of limitations in terms of communication and road structure.

"We saw a TV debate as useful because it crosses barriers in terms of literacy and candidates can talk to voters in their own homes."

'Show of weakness'

Before the debate, Haroun Mir, the deputy director of the Afghan Centre for Research and Policy Studies, said Karzai knew very well that if he took part in the debate, he would "face criticism from the two other candidates".

"For the past five years, as leader of Afghanistan, he has not been successful. It will be very difficult for him to defend what he has accomplished in the past five years. That's why he is trying to avoid direct debate," Mir told Al Jazeera.

Ajmal Habidy, Ghani's aide, said: "If President Karzai is not participating in the debates, it shows his weakness."

Though Karzai's popularity has slipped in recent years, no challenger is expected to be able to defeat him in the election unless they combine their campaigns and back a single candidate.