Just six months ago Lee himself scored the biggest landslide win in the history of South Korean presidential elections, but he is now facing plummeting popularity levels.
Thursday's opening of the National Assembly was to have seen the election of a new speaker, MPs taking the oath of office, and then a traditional speech by the president.
But those plans unravelled after most opposition politicians failed to show up.
The row comes after Lee's government signed a controversial accord in April to resume importing US beef.
|Lee has seen his popularity slump since his |
election in December last year [AFP]
The deal has come under fire amid widespread public perceptions that it fails to offer sufficient protection from possible mad cow disease by allowing imports of beef from older cattle, considered at greater risk of the brain-wasting illness.
Opponents of the deal have held daily street protests demanding that the US deal be scrapped or renegotiated.
Earlier this week, the government announced that it had asked the United States to refrain from exporting any beef from cattle above 30 months old, but it stopped short of asking for a full renegotiation of the deal.
The opposition has denounced that arrangement saying it is a diversionary ploy to calm public anger.
They have said they will accept nothing less than the scrapping of the current deal and the renegotiation of a new one.