Democratic Party of Japan leaders on Wednesday discussed options for cooperating with the Liberal Party, including a possible merger, but put off a decision until next week over fears of splitting the DPJ.

After the executive meeting, DPJ President Naoto Kan told a regularly scheduled news conference that the party’s secretary general, Katsuya Okada, made four cooperation proposals:

* Merging the two parties at all levels.

* Merging only Lower House lawmakers.

* Forming a joint parliamentary group in the Diet after an election.

* Cooperating only in election campaigns.

Many Liberal Party lawmakers are expected to face uphill battles in the next general election and are therefore seeking a merger with the DPJ, the largest opposition force.

The Liberal Party has urged the DPJ to make a final decision by May 9. The next executive meeting of the DPJ is scheduled for May 6.

Kan declined to say which option he favors most, apparently because some DPJ lawmakers have threatened to leave the party if it merges with Liberal Party.

Kan also admitted that the merger talk has failed to generate public interest.

“Frankly speaking, we haven’t felt much enthusiasm from the voters,” Kan said.

Kan and Okada have sought ties with the Liberal Party to help push the ruling Liberal Democratic Party out of power in the next general election.

The Liberal Party is headed by Ichiro Ozawa. The DPJ includes many conservative lawmakers from Shinshinto, formerly the largest opposition party. Shinshinto broke up in 1997 due to internal conflicts over Ozawa’s leadership.