Deputy Prime Minister Katsuya Okada has sounded out the Liberal Democratic Party about forming a grand coalition with his ruling Democratic Party of Japan, possibly hinting at an early general election, political sources said Saturday.

But the two sides remain far apart. Okada is demanding that the LDP cooperate to enact bills over a sales tax rise and the issuance of deficit-covering bonds before any snap election, but the largest opposition party wants an election to precede the passage of this legislation, they said.

The LDP's leadership is expected to respond after closely gauging opinion among the party's lawmakers, given their steadfast calls to pressure Prime Minister Yoshihiko Noda into calling a snap Lower House election.

If the concept of a grand coalition progresses, it could prompt some of the DPJ's members — especially those who oppose the tax hike and are close to former party leader Ichiro Ozawa — to quit the party. It might also cause the LDP's opposition ally, New Komeito, to object.

But any alliance apparently only would last until the tax hike legislation cleared the divided Diet, where the opposition controls the weaker Upper House. The two parties would then dissolve the partnership and compete in the election as usual, the sources said.

Since reports surfaced that Noda and LDP President Sadakazu Tanigaki held secret talks Feb. 25 about coordinating the tax hike, executives from both parties have met frequently behind the scenes, they said.

Some officials from the LDP appear receptive to a grand coalition as a way to get Noda to dissolve the Lower House for a snap election.

But both sides have expressed concerns about a short-lived coalition, mainly over the potential confusion it might cause if the two parties then campaigned on different policy platforms.