SINGAPORE Democratic Party leader Chee Soon Juan, on trial for speaking in public without a permit, probed into the legality of his actions when he cross-examined a police officer in court on Wednesday.

If what he did was so illegal, why did Station Inspector Charles Soon allow him to continue, he wanted to know.

Chee and party supporter Yap Keng Hoe are on trial for speaking in public without a permit last year in the run-up to the General Election.

Summing up his defence on Wednesday, he repeatedly asked SI Soon, who was at the scene, why he did not check with the SDP group if they had a permit.

If the police knew a permit was required, why did they not make any attempt to 'stop us', Chee said.

Replying, SI Soon told the court that although the crowd was 'generally well-behaved', there was a possibility of disorderly behaviour.

Chee accused him of evading his question and tried again to get an answer from him as to why he did not ask them if they had a permit.

District Judge Jasvender Kaur disallowed the question, explaining that it had 'no relevance' to Chee's defence.

Earlier, Yap claimed he was not addressing the public but merely trying to sell the party's newsletter.

But he echoed Chee later, when he also blamed the police for not approaching them.

'The police officers were hiding... and didn't talk to us. Other officers in previous incidents would approach us and we were happy to cooperate and adjust our plans accordingly. But in this case, the officer did not do so,' he said.

The trial continues.

If convicted, Chee and Yap could each be fined up to $10,000.