Despite the agreement, skepticism lingers over the prospects of any cross-party agreement, as the rival parties showed no signs of budging over the revision.

The Democratic Party further pressed opposition parties to deliver on their election pledges last year to put a revision bill to a referendum at the same time as the June 13 local elections.

But the LKP reacted furiously to the government bill, accusing the liberal president of "unilaterally and hastily" pushing for the revision to codify "leftist" views and create a favorable political climate ahead of the local elections.

The government submitted to the legislature its proposal for the revision, including changing the current single five-year presidential term to a maximum of two successive four-year terms -- a major fault line in the amendment debate.

The parliament must handle the proposal by May 24, as the current law states that a constitutional revision motion must be put to a vote within 60 days of the public notification that coincides with its submission.

Should the parties craft their joint revision bill, they have to submit it by May 4 to ensure that it can be put to a plebiscite concurrently with the local elections.

"Beyond partisan interests, political circles must prepare for the revision through conscientious discussions so as to keep our pledge to conclude the revision by June," Choo Mi-ae, the ruling party's leader, said during a party meeting.

"All in politics have the obligation to enshrine people's aspirations (for the revision) into the Constitution," she added.

The LKP, however, hardened its rhetoric against the ruling bloc, claiming that the government proposal was hastily cobbled together and that the revision must be led by the parliament, not the government.

"That is a unilateral submission that involves no consultation with the parliament," Hong Joon-pyo, the LKP leader, said during a party meeting. "We will make due preparations and consider a national movement to resist it."

The firebrand LKP leader has also lambasted the government proposal as a "show for socialist revision."

His party has taken issue with the proposal's inclusion of the public concept of land that provides the rationale for restricting private ownership for the sake of public interests. It argues that the concept conflicts with free market principles.

A key sticking point concerns the government structure.

The LKP advocates a power-sharing model in which more authority is given to the prime minister picked by the parliament, arguing that any revision must address the current concentration of power in a single leader that has been blamed for corruption and power abuse.

Minor parties such as the centrist Bareunmirae Party have warmed to the idea of the premier grabbing more authority.

But the ruling party argues the dispersion of power could cause disruptions in the management of state affairs, particularly when the country faces a constant security challenge from a provocative North Korea.

It also claims that concerns about the concentration of power in the presidency can be mitigated through proposed clauses such as bolstering the parliament's legislative and budget oversight rights.

The timing of the referendum is another thorny issue.

The ruling bloc maintains that a referendum must be held concurrently with the local elections in line with last year's presidential campaign pledge and to save costs. But the LKP says talks must continue until the term of the special parliamentary panel on the revision ends in June.

A constitutional revision needs approval from two thirds of all 293 lawmakers in a parliamentary vote and from a majority of voters in a referendum. The ruling party has only 121 seats, far short of the 196 seats required for the passage of the revision bill. (Yonhap)