Aung San Suu Kyi has won Myanmar’s landmark election and claimed a staggering majority in parliament, ending half a century of dominance by the military and providing the symbol of a decades-old democracy movement with a mandate to rule.

The government’s election commission in the capital of Naypyidaw said the National League for Democracy (NLD) party had won 348 seats across the lower and upper house of parliament, 19 more than the 329 needed for an absolute majority.

In the latest standings, the incumbent military-backed Union Solidarity and Development party (USDP) has taken just 40 seats across the two chambers. Minority parties won a handful of further seats.

With only 83% of the results announced so far this week, the NLD’s majority is likely to rise yet further.

Although Aung San Suu Kyi is banned from the presidency under an army-drafted constitution, her party will now be able to push through legislation, form a government and handpick a president. Aung San Suu Kyi, who spent years under house arrest, has said that a triumph for the NLD would place her "above the president”.

An NLD government would be the first administration not chosen by the country’s military establishment and their political allies since the early 1960s, most of that time under army dictatorship. Months of political haggling will now begin as the nation is drastically reordered.

The current leaders and military figures have signalled they will accept the overwhelming defeat, stamping out fears of a repeat of the 1990 election. Aung San Suu Kyi won that poll but the results were promptly annulled and her colleagues imprisoned.

On Thursday, the headline for the state-run Global New Light of Myanmar newspaper read: "Welcoming the New Guard.”

The president’s spokesman said on Wednesday that the government would obey the results and work to transfer power peacefully, after offering congratulations to Aung San Suu Kyi.

"We will respect and obey the decision of the electorate,” Ye Htut, also the minister of information, said on his Facebook page. "We will work peacefully in the transfer [of power]. Congratulations … to the chairperson Aung San Suu Kyi and her party for gathering the support of the people.”

Myanmar’s commander-in-chief Min Aung Hlaing also sent congratulations.

Aung San Suu Kyi does not have complete power and the army generals, who have amassed billions of dollars in wealth, will still control the most powerful ministerial portfolios – interior, defence and border affairs.

The Myanmar armed forces, or Tatmadaw, also has an automatic hold of a quarter of seats in parliament, meaning the opposition needed to win at least 329 seats to make up a majority (67%) of both houses.

Many in the country of 51 million hope the NLD will push through political reforms but also develop the country’s struggling education and health systems, and create jobs in south-east Asia’s poorest nation.

US president Barack Obama called Suu Kyi to congratulate her and her party’s successful campaign and also spoke to president Thein Sein to commend him on the historic polls, the White House said.

Aung San Suu Kyi invited the army chief, president and the parliamentary speaker to discuss the election and has said she will form a national reconciliation government.

Aside from the 25% of seats ringfenced for the military, there were 168 contested seats in the upper house of parliament and 330 in the lower house, although seven of those lower house seats were cancelled due to fighting with insurgent groups in border areas. That amounts to a total of 491 seats contested in both houses.

The NLD has also won significant majorities in the regional and state assemblies.