Australians, up in arms over the 20 year sentence handed to Schapelle Corby on Friday, are threatening to boycott their nearest neighbour.

Brisbane's Courier Mail says callers to talk-radio stations are urging their fellow Australians to boycott Indonesia and Indonesian products.

The 242 million-strong country north of Australia has come under attack following the arrest of 27 year old Corby in October last year on charges she was smuggling 4.1 kg of marijuana into the resort town of Bali. Corby maintained the drugs were not hers and they must have been planted by baggage handlers. In recent weeks those claims were buoyed by an Australian Federal Police investigation which resulted in drug charges being laid against a number of Qantas baggage handlers. The three judges though that sat on the Corby case maintained she had been caught red-handed and had showed no remorse. One of the judges has been hearing drug cases for more than two decades and by his own admission has never handed down a 'not guilty' verdict.

Particularly disturbing to Australians has been the severity of the sentence in light of the sentences handed down to men convicted in the Bali bombing case. The horrific October 2002 blast killed 202 people, 88 of whom were Australians.

Australians are huge visitors to Bali and had only in recent months begun returning to the resort after numbers fell off dramatically in the aftermath of the bombing.

Radio callers since Friday's verdict and sentence are now calling for Australians to destroy Bali's economy by turning it into a 'ghost town'.

'Certainly never go to Bali again – I certainly won't and I'll be encouraging my friends and family not to,' one of many callers told Brisbane radio 973FM.

The Courier Mail said Federal police upgraded security at Indonesian missions after the Canberra embassy was bombarded with hate phone calls.

Prime Minister John Howard expressed sympathy for the Corby family but urged calm and respect for the Indonesian justice system.

'Guilty or innocent, I feel for this young woman,' he said.

'Whatever additional assistance that can appropriately be provided will be. But at the end of the day we must, and the Government will, respect the processes of the justice system of other countries.'

The scenes in the Denpasar court on Friday were televised live in Australia, while more than 100 journalists had flown to the resort for the decision. Corby's face crumpled with anguish and her family screamed abuse as the judges declared her guilty.

Looking bewildered, Corby reportedly mouthed the words '20 years' and put her head down.

Chief judge Linton Sirait said: 'The accused is proven legally and convincingly guilty of committing the crime, without right and against the law, of importing type-one narcotics.

'Deliver the sentence to the accused Schapelle Leigh Corby the jail term of 20 years and the fine of 100 million rupiah ($14,000). If the fine can't be paid, six (extra) months in jail.'

The judges ruled out the testimony of all the defence witnesses and said Corby could not 'avoid responsibility for the existence of the plastic bag containing marijuana in the boogie board bag'.

They said they had found little to make the sentence lenient, except that Corby was young and had no criminal history.

From the front of the gallery, Corby's parents and sister realised before her what the chief judge was saying and erupted with abuse and emotion. Caught in the middle, Corby swayed between distress, tears and hot anger.

Her mother Rosleigh Rose screamed at the judges: 'You took the word of a liar, these judges will never sleep – Schapelle you will go home, we will bring you home.'

Corby tried to calm the situation: 'Mum, it's OK, Mum it's OK, Mum, stop OK!'

She then turned, shaking and yelling at prosecutor Ida Bagus Wiswantanu to find who planted the drugs in her bodyboard bag.

Indonesians outside court clapped the guilty verdict, prompting an outburst from Corby's sister Mercedes.

The sentence was the first step in a long road through the Indonesian justice system.

Both the defence and prosecution will launch appeals, and an Australian Government team will travel to Indonesia on June 6 to negotiate a prisoner exchange deal. The appeals are expected to take at least 18 months, and Corby would not be transferred to an Australian prison before 2007.

The opposition-Australian Labor Party, has written to the Indonesian Government asking for a presidential pardon for Corby on humanitarian grounds.

Corby's Indonesian legal team visited her in Kerobokan Jail, where she was taken immediately after the verdict. They said she was strong and had pledged: 'This is not over yet, we will fight together.'

But an emotional Lily Lubis, who headed the defence team, said Corby – who has already spent eight months behind bars, – could die if forced to serve the term in an Indonesian jail. 'I know for sure she will not survive this sentence,' Ms Lubis said.

Defence lawyer Erwin Siregar said an appeal against the verdict would be lodged with the High Court in Denpasar next week, the Courier Mail reported.