(Telecompaper) A group of US Congressmen has made a last attempt to halt the planned transition of ICANN to an independent organisation, outside US government control. The handover is expected to take effect from 01 October, but four Congressional chairmen have asked the Commerce Secretary Penny Pritzker and Attorney General Loretta Lynch to stop the process. They are concerned that the new ICANN organisation lacks accountability, and claim the government should have sought Congress' approval before handing over the contract to manage the internet naming system. In response, leading tech companies including Amazon, Google, Facebook and Twitter sent their own letter to Congressional leaders, The Register reports. They want the transition to proceed and called on Congress not to intervene. By 15 September, the US is contractually obliged to informa ICANN whether it will go ahead with the transition. According to opinions from the US Government Accountability Office, President Barack Obama may take he decision to sign off on handing over ICANN's management.