The Thailand Consumers Council (TCC) and the opposition Move Forward Party (MFP) will ask the Administrative Court to issue an injunction against the planned merger between telecom operators True Corporation and Total Access Communication (Dtac), citing monopoly concerns.
They said they will also ask the National Anti-Corruption Commission (NACC) to look into whether there was any dereliction of duty by the National Broadcasting and Telecommunications Commission (NBTC) regarding the merger.
Saree Aongsomwang, TCC secretary-general, expressed disappointment yesterday with the NBTC's decision to not shoot down the merger.
She said the NBTC merely acknowledged the planned merger and did not exercise its power.
The board of the telecom regulator has been divided over whether it has the legal authority to block the merger, or whether it can only set certain conditions to ensure fairness.
However, Ms Saree said the Administrative Court and the Council of State have ruled that the NBTC has the legal authority to block the merger, but the majority of NBTC members voted otherwise.
"This could be deemed as a dereliction of duty," she said.
She said the TCC will seek an Administrative Court injunction and seek a ruling. It will also ask the NACC to investigate, she said.
"Apart from the TCC and the MFP, other damaged parties, including customers of True and Dtac, can join petitions if they have receipts," she said.
Sirikunya Tansakun, deputy leader and a list-MP of the MFP, said the NBTC has in this case failed to protect consumers and prevent a monopoly from forming.
The party plans to join pro-consumer groups by petitioning the Administrative Court and the NACC, she said.
She said the party will wait to hear the opinions of all NBTC members and use them as evidence to file a petition asking the NACC to look into the matter.
A source at the NBTC said after emerging from the meeting room that a decision was reached whereby it has no authority to consider approving or rejecting the planned merger.
The mega deal was announced by Norway's Telenor, the parent of Dtac, and conglomerate Charoen Pokphand (CP) Group, the parent of True, at a joint press conference last Nov 22.
The regulator was expected to make a call on the deal on Thursday that consumer rights groups said would reduce market competition.
The merger would result in a duopoly with only two major players in the market and consumers paying higher service fees, they said.
While consumer rights groups called on the regulator to reject the merger, True and Dtac stressed the NBTC only has the legal authority to prescribe specific measures to govern the deal.
The regulator was expected to impose tough measures to govern the merger.
If it goes ahead, it would create the country's largest mobile operator with a market share of about 56%, versus 44% for the current market leader, Advanced Info Service Plc (AIS).
Reports commissioned by the NBTC recommended it be "prohibited".