Lt Gen Anantaporn Kanchanarat, head of the state budget monitoring and scrutinising committee, said several of these projects are deemed unnecessary and need reviewing.
He said the agencies concerned have been ordered to assess them and submit reports as soon as possible. The panel is expected to finish prioritising projects by June 30.
All 28 projects costing more than a billion baht each are covered by the 2014 fiscal budget, Lt Gen Anantaporn said.
Two involve construction of reservoirs by the Royal Irrigation Department. The RID has been asked to review the reference prices and the cost benefits.
The move to scrutinise the 28 projects followed the junta's decision on Monday to review eight budget-intensive infrastructure programmes for transparency.
Starting from the 2015 fiscal year state agencies must disclose all of their procurement and purchase schemes for public scrutiny. The scrutinising committee will ensure the reference pricing system is better regulated, Lt Gen Anantaporn said.
He said the panel has asked the National Broadcasting and Telecommunications Commission to revise its digital television coupon subsidy. The NBTC plans to distribute 1,000-baht coupons to households nationwide to promote the switch from analogue to digital television.
He said the committee wants the NBTC to lower the coupon value from 1,000 baht.
Meanwhile, Anti-Corruption Organisation of Thailand chief Pramon Sutivong has urged the NCPO to probe the 240-billion-baht purchase of new aircraft for Thai Airways International.