Senior figure deserts Japan's LDP

Yoshimi Watanabe, who has quit Japan's ruling Liberal Democratic Party

There is speculation that Mr Watanabe could trigger further defections

A senior politician has quit Japan's ruling Liberal Democratic Party (LDP), in the latest blow for the party and embattled Prime Minister Taro Aso.

Yoshimi Watanabe, a former cabinet minister, questioned Mr Aso's political judgment and said he feared Mr Aso could "invite tragedy" to Japan.

Mr Watanabe was a vocal critic of an LDP-backed supplementary budget which will see the public get cash handouts.

His demands that the long-dominant LDP call a snap election were also ignored.

The charismatic, if gaffe-prone, Mr Aso was elected leader of the LDP in September in a move the party hoped would shore up its public standing.

But recent polls now suggest Mr Aso's popularity is languishing below 20%, raising the spectre of an electoral defeat for the LDP, which has only been out of power a few months in the last 50 years.

Mr Watanabe's resignation will raise fears in the LDP that more could follow.

'Change needed'

Mr Watanabe announced his resignation from the LDP at a packed news conference.

"Prime Minister Aso's political judgment, which is only based on his desire to hold on to power, is the very problem that is delaying measures on crucial issues," Mr Watanabe said, according to AP news agency.

"I fear that he might invite tragedy to the country and its people."

He said the prime minister was out of touch and that a change was needed "fast".

One of Mr Watanabe's key bones of contention with the ruling party is its attempt to rescue Japan's ailing economy by spending.

A 12-trillion-yen ($135bn; £92bn) second supplementary budget designed to try to stimulate the economy was passed by the budget committee of the lower house of parliament.

Of that, two trillion yen will be passed to the public in cash handouts - something Mr Watanabe says is a gimmick that will do little to get the country out of recession. Mr Aso has rejected the criticism, saying extraordinary measures are needed for this "once-in-100-years event".

Unless Mr Watanabe can attract a significant number of LDP members to follow him, the bill remains likely to come into force, as the LDP still retains a two-thirds majority in the lower house of parliament.

The LDP must hold elections by September, but amid its poor poll ratings Mr Watanabe's demands for a snap election have also been ignored.