At the Damnoen Saduak floating market on the outskirts of Bangkok early last Sunday morning, veteran Thai politician Chaturon Chaisang worked his campaign charm on a captive audience of stall keepers and boat owners.

Accepting marigold garlands and red roses from supporters, the former Thai deputy prime minister, 63, raised a smile from locals and foreign tourists as he unsteadily lifted an oar and began to navigate a low, flat boat filled with party officials through a cluster of floating vendors selling mangoes and sticky rice.

In an earlier interview with The Telegraph over a strong coffee, Mr Chaisang said that he and his Thai Raksa Chart [TRC] party, one of the main opposition forces contending Thailand’s March 24 poll, wanted to present voters with a manifesto focussed on the “economy, economy, economy.”

However, they may be denied the chance to do so. On Thursday, Thailand’s constitutional court will rule on whether the TRC should be dissolved for making a dramatic play last month to nominate King Maha Vajiralongkorn’s sister as its prime ministerial candidate.

The surprise attempt to field Princess Ubolratana Rajakanya sparked uproar in a nation where the royal family is revered and regarded as above politics.