Burmese security forces surrounded the headquarters of the ruling Union Solidarity and Development party on Thursday and senior regime figures were removed from their posts as tensions mount ahead of elections in November.

Sources within the headquarters of the USDP – which is effectively a political extension of the military – said Shwe Mann, party chairman and speaker of the parliament, had been deposed and was under police guard. His closeness to opposition leader and democracy figurehead Aung San Suu Kyi is believed to have soured his relationship with military leaders in Burma, also known as Myanmar.



The developments serve as a reminder that the military still wields considerable power, and make it more like that President Thein Sein - a retired general and the army’s choice of leader - will serve a second term.

In 2011 a nominally civilian government took over in Burma led by Thein Sein, who initiated political and economic reforms but has stopped short of challenging the military’s constitutionally protected role in politics.

“Police entered the party compound last night. Since then no one was allowed in or out,” Toe Naing Mann, Shwe Mann’s son, told Agence France-Presse. “So-called guards” were also outside his father’s residence in the capital, Naypyidaw, he said.

Several trucks of soldiers and police officers arrived at the compound at about 10pm on Wednesday, sources said. “We have not been allowed to move around since late yesterday,” said one party member.



The USDP general secretary, Maung Maung Thein, was also forced from his post. “They called me and told me I don’t need to come to the office anymore,” he told Reuters.



#BREAKING: #Myanmar ruling party Secretary General Maung Maung Thein says has been removed from his position, @Reuters reports — Sri Jegarajah (@cnbcSri) August 13, 2015

The moves comes during a tussle for control of the USDP. Tension has reportedly risen between leaders of the military-backed government over the selection of candidates to run in the 8 November general elections.

Christian Lewis, a political risk analyst for Eurasia Group, said a faction in the party loyal to Thein Sein appeared to have finally moved decisively against Shwe Mann after a long-running power struggle.



“In terms of the election, these events strongly support the idea that Thein Sein will seek a second term for president,” he said.

The British embassy said on its Facebook page: “We are concerned by reports that the police were involved ... in the resolution of a party dispute. Public trust in the democratic process is essential as we approach the elections in November.”

The elections – which had been touted as potentially the most free in decades – are set to be contested by Aung San Suu Kyi, who was a thorn in the side of the previous junta regime with her years of campaigns for democracy.



Recent months have seen growing talk of animosity between Shwe Mann and Thein Sein, both former generals who shed their uniforms to take part in controversial 2010 polls that heralded a new quasi-civilian government, which has ushered in sweeping reforms.



Tensions began to heighten earlier this week when the USDP, now choosing its candidates for the election, overlooked some senior military officials during a party convention. A group of 149 army officers had resigned their posts on Wednesday hoping to take part in the election but only 59 were approved as candidates.

Thein Sein, Burma’s president. Photograph: Reuters

The leading local political commentator Yan Myo Thein called Shwe Mann’s removal a “purge” and warned that the party’s internal strife had the potential to disrupt progress towards democracy.

“I think primarily that is the ruling party’s internal affair, but the internal struggle of the ruling party can threaten the democratisation process of [Burma],” he said. “Because of the power struggle and incidents inside the ruling party, the upcoming general election can be postponed. If the election is postponed the process of democratisation in Myanmar will be delayed.

“People are expecting to have a new government made up of the majority opposition [the National League for Democracy] and the ethnic minority parties.”

Yan Myo Thein said it was so far unclear whether the purge was initiated by serving military officials. “Most of the leaders are retired military generals so that they may have direct or indirect relations with the serving military generals,” he said. “But I’m not sure of the role of the military in the recent purge.”

The move comes after years of rumours of a split in the ruling party between Thein Sein and Shwe Mann – the latter seen as being close to Aung San Suu Kyi. A recent petition backed by military officials sought to impeach Shwe Mann for his role in proposing amendments to the military-drafted constitution, which were anyway rejected.

Myanmar pro-democracy leader Aung San Suu Kyi talks to the media as Shwe Man, Speaker of the parliament, sits beside her at a joint news conference in March 2014. Photograph: Soe Zeya Tun/Reuters

U Nyan Win, a spokesman for Aung San Suu Kyi’s party, the National League for Democracy, said the party was not involved in events in Naypyidaw and declined to speculate on the reasons behind it.

He noted, however, the deadline for political parties to decide their candidate lists for election. “The last day is tomorrow [Friday] but we don’t know what is happening with them,” he said. “We are just finalising our own list now.”

The USDP has been the vehicle for the former junta elites to metamorphose from soldiers to MPs. But there is internal tension over the speed of democratic reforms and the loosening of the military’s grip on power, which it has held for more than half a century.

Shwe Mann has welcomed the idea of working closely with Aung San Suu Kyi and has set himself up in opposition to the still powerful army on key issues – including on the constitutional reform debates that have centred on reducing the military’s political power.



The Nobel laureate Aung San Suu Kyi – the daughter of Burma’s independence hero General Aung San and the country’s democratic icon for a generation – led her party, the National League for Democracy, to victory in Burma’s election in 1990, but the party was never allowed to take power.



She spent 15 of the next 21 years under house arrest and was banned from standing in Burma’s first elections in a generation, held in 2010, leading to an NLD boycott of the poll. She was still under house arrest at the time of the election, until released a week later, and has since been elected to parliament in a byelection.



Her participation in this year’s election is being seen, both inside Burma and out, as a major step forward in the country’s democratic reforms. She has vowed that if the NLD wins, it will amend the constitution to weaken the military’s hold on parliament. But military figures are expected to remain significant political players.

Reuters and Agence France-Presse contributed to this report