City Hall plans to charge a fare of up to 59 baht for the BTS Skytrain Green Line electric rail service, drawing criticism from a consumer protection group which says the fare should not exceed 44 baht.

Bangkok governor Chadchart Sittipunt said on Tuesday the Thailand Development Research Institute (TDRI) has recommended City Hall collect a fare of up to 59 baht for the entire route including the Green Line's extension.

That covers routes from Bearing to Kheha stations and from Mo Chit to Khu Khot. There is currently a free ride programme along the two routes.

He said up to 27% of passengers get free rides on the extended routes and City Hall has to use other taxpayers' money to cover the costs.

He insisted the proposed 59-baht fare has nothing to do with his campaign pledge that fares would range from 25-30 baht. "The rate of 25-30 baht is not for the entire route. This is an average rate for a ride along eight stations," he said.

"BMA executives have agreed that the 59-baht fare is suitable because the extended routes are quite long," Mr Chadchart said.

The Thailand Consumers Council (TCC) said the fare for the whole route should be capped at 44 baht, similar to the rates charged for other electric rail systems.

The new rate would see commuters pay up to 118 baht for daily round trips, which would be 36% of the minimum daily wage (331 baht) for workers in Bangkok, the TCC said.