Senior Congress leader and former Defence Minister A.K. Anthony on Wednesday attacked the Centre, saying demonetisation and GST had ruined the economy and the only way it could be set right was to ensure that the Modi government is defeated in the next Lok Sabha polls."Our foremost expert Manmohan Singh had warned Modi to delay the implementation of GST by at least six months, but they went ahead, and see it has ruined our economy. Now for things to change, the only way out is to see that Modi is made to sit in the opposition after the next Lok Sabha polls," said Antony.Addressing reporters here ahead of flagging the state-wide Congress yatra being led by Leader of Opposition Ramesh Chennithala and accompanied by top leaders of the United Democratic Front, Antony also alleged that the BJP and the ruling CPI-M are in cahoots in order to weaken the Congress.The yatra, that will pass through all 14 districts and reach the state capital on December 1, is to highlight the "anti-people policies" of the state and central governments."Today the BJP and CPI-M are in public attacking each other, but when it comes to action they are soft. We have seen that state ministers from Kerala when in Delhi dine with BJP leaders. Their single point agenda is to weaken the Congress," said Antony."Today in the CPI-M politburo there are seven from Kerala, and the BJP and the CPI-M are working to reduce the number of Congress MPs from Kerala in the next Lok Sabha polls. The BJP is working to get more seats for the CPI-M in the Kerala Assembly, while the CPI-M is working to see that not a single Congress MP from here goes to Delhi. The CPI-M is working hard to see that there is no united opposition against the BJP," added Antony.