BANGKOK- Thailand's Deputy Public Health Minister resigned on Sunday after being implicated in a corruption scandal over a $2.57 billion (1.6 billion pound) healthcare scheme.

Manit Nopamornbodee was the second minister to quit over the high-profile scandal, which has embarrassed an embattled coalition government as it prepares to face mass street protests and a no-confidence motion in parliament.

Public Health Minister Witthaya Kaewparadai, a member of the ruling Democrat Party, stepped down on December 29 but the refusal of his deputy to follow suit had highlighted tensions within a six-party coalition fraught with bitter infighting.

With the backing of his Bhumjai Thai party, the second-biggest coalition partner, Manit had ignored calls by Prime Minister Abhisit Vejjajiva to quit in what analysts said was a sign of growing disunity in the government.

I insist that I have never involved in this so-called corruption case, however, I have to resign to show my responsibility and to reduce political pressure on my Bhumjai Thai party, Manit told reporters.

Four ministers have resigned, three over corruption scandals, since the government took office a year ago, citing graft-busting as one of its priorities.

Abhisit said on his weekly television address on Sunday that he would finalise a list for a minor cabinet reshuffle later this week.

A fact-finding panel last month recommended Witthaya, Manit and nine other officials be disciplined for backing ministry plans to build facilities and buy medical equipment deemed unnecessary or grossly overpriced by local health officials.

Manit came under particular scrutiny for the amount of money allocated for construction of car parks, medical wards and the purchase of ambulances at inflated prices in his constituency of Ratchaburi province.

The health project came under the government's $43 billion economic stimulus package, aimed at speeding-up economic revival but also seen as a move to boost the government's popularity.
The scandal will provide fodder to anti-government protesters planning a rally at the end of this month, which they say will be their biggest yet in their campaign to unseat the government.

The red shirt protests by supporters of ousted former premier Thaksin Shinawatra are planned to coincide with a censure motion in parliament led by the opposition Puea Thai party, which the twice-elected billionaire backs from exile.

Concerns about a violence during the protests have had an impact on markets in Southeast Asia's second-biggest economy, which suffered downgrades to its sovereign credit ratings as a result of previous clashes.

(Reporting by Boontiwa Wichakul; Writing by Apornrath Phoonphongphiphat; Editing by Martin Petty)