A senior United Nations official expelled from Burma this week warned on Wednesday that a “more volatile situation” lay ahead if the country’s military regime refused to recognise that recent mass protests stemmed from common people’s anger over economic woes.

In an interview with the Financial Times, Charles Petrie, who until his expulsion on Tuesday was the most senior UN official in Rangoon, warned that without substantive reforms the Burmese junta could be forced to resort to greater repression to keep control over a restive population.

“It’s very dangerous for the regime not to understand the grievances that people expressed on the streets,” Mr Petrie said. “People came out [to demonstrate] because the pain they are feeling is too much – they are suffering.”

The regime’s refusal to acknowledge these fundamental grievances, and continued repression, were “a pretty bad cocktail”, he said. “It creates the conditions for an even more volatile situation, which the regime will only be able to contain by increasing violence and intimidation.”

Burma’s military rulers stunned the international community last month when they abruptly announced that they were ejecting Mr Petrie. The move followed the release of a statement by the UN country team in which it said the September protests reflected widespread frustration “at the everyday struggle to meet basic needs” and called for the junta to address a “deteriorating humanitarian situation”.

The generals – who have characterised the mass protests as a CIA plot to overthrow them – accused Mr Petrie, who was the UN humanitarian co-ordinator and Development Programme representative, of “acting beyond his capacity by issuing a statement that harms [Burma’s] reputation”.

Mr Petrie, who was granted a month to leave to ensure an “orderly transition”, said the move against him was part of the regime’s broader campaign to harass its critics and browbeat the local population.

“My expulsion is part of the intimidation,” he said.

Mr Petrie’s comments came as the military toughened its stance towards its domestic and international critics, after making a few conciliatory gestures following the global outcry at their suppression of the protests.

On Monday Brig-Gen Kyaw Hsan, information minister, rejected calls by Ibrahim Gambari, the UN special envoy for Burma, for the regime to engage in a dialogue with Aung San Suu Kyi, the Nobel Prize-winning democracy advocate, on a new constitution.

In a rare press conference, the minister said the regime was moving ahead and did not need “assistance and advice from other persons”.