A long convoy of rice farmers from four central provinces is heading to Bangkok to demand for unpaid subsidy for pledged rice.As of 6 pm, they have reached Ayutthaya and they are expected to enter Bangkok Friday.The total number of them is estimated at 15,000, who are travelling in 1,000 tractors and improvised farm vehicles.Former Chat Thai Pattana Party MP ChadaThaiset, who represents UthaiThani-based farmers, said that part of the farmers would be heading to Suvarnabhumi airport, on purposes he did not specify.A leader of Lop Buri-based farmers, UbolsakBualuangngarm, said farmers would blockade the capital for seven days if the government failed to pay them, but would not cooperate with anti-government movement People's Democratic Reform Committee in its drive to oust the government. He also asked capital residents to stockpile food supplies for seven days before then."If the goverment wants to disperse farmers' protests or arrest us. All of us are ready to die, and donate our bodies, if the government wants to do anything to farmers," he said, adding that the farmers travelling with this convoy would be joined by those travelling from the Northeast and the West who are expected to reach Bangkok Friday.