Plans by senators to go overseas on trips costing millions of baht have come under fire as their terms end on May 10.
Plodprasop Suraswadi, a former deputy prime minister, and outspoken Senator Seree Suwanpanont, have encouraged the senators to call off their trips.
Mr Plodprasop said that senators' upcoming overseas study trips will cost 81 million baht in total.
He said they have less than a month before their Senate tenure ends, and such trips make little sense.
The Senate's committee on armed forces and state security, chaired by Gen Boonsang Niempradit, for instance, plans to go on a trip to Kazakhstan and Georgia on May 2-9 for bilateral meetings, said Mr Plodprasop.
Among other overseas trips planned include a trip to Croatia, Montenegro and Bosnia on May 14-23, which will come after the Senate's tenure has ended, according to Mr Plodprasop.
Another trip is planned to be carried out from May 27 to June 3 for bilateral meetings and a study tour focusing on artificial intelligence development in Finland, Sweden and Estonia, he said.
"Believe me once, will you? As an old friend, I'd suggest you (senators) cancel your trips, or else these trips will ruin all the integrity you have maintained," he said.
Gen Boonsang has defended himself and other senators intending to join such trips, saying spending the state budget to fund them is fully worthwhile as they are aimed at acquiring information and knowledge which will benefit these senators' future work.
He said the 81 million baht isn't that much, given the number of trips and participants is large.
Such trips should have been carried out earlier but were put on hold due to the Covid-19 pandemic, he added.
"Please don't view these trips as leisure trips being done because our tenure will end soon. As senators, we had avoided as much as possible making a study trip overseas; sometimes we passed a lame law due to a lack of first-hand experience," he said.
These trips are also aimed primarily at building new bilateral cooperation, he said.
The trip he is going on is only the second he has been on in five years, Gen Boonsang said.
Mr Seree said he couldn't agree with all the planned trips.
"When it comes to spending the state budget, we have to be extra careful and set a good example," he said.
Mr Seree said he has, from time to time, pushed for the cancellation of all overseas trips of the Senate, which was supported by some and opposed by others in the Upper House.
Move Forward Party MP for Chachoengsao Jirat Thongsuwan on Friday expressed doubts about the worthiness of the Senate committees' overseas trips, given that the Senate's term is due to end next month.
He questioned whether those planned trips would benefit taxpayers, as the Senate committees claim that such study trips would allow them to gain knowledge for national development.
"There's no time left for them to work and develop the country. However, if such trips are open to public examination for the sake of transparency, it shouldn't be a problem," he said.
According to Mr Jirat, the Senate committee's overseas study trips seem more like leisure trips rather than serving their intended purpose. However, he said there is little the public could do to stop such trips.
Mr Jirat also expressed concerns the new Senate might not have enough funds for future overseas study trips.