Senior Democratic lawmakers called for tougher gun laws in the wake of the deadly shooting at an elementary school in Connecticut, as they tried to jolt a paralysed US political system into action to prevent further bloodshed.

But finding political consensus for tougher gun laws will be an uphill struggle for Barack Obama. Republicans, generally opposed to tightening restrictions on gun ownership, control the House of Representatives, and even some Democratic senators running for re-election in conservative states in 2014 may not support new legislation.

However, Dianne Feinstein of California, chair of the Senate Intelligence Committee, said that on the first day of the new Congressional term in January she would introduce a bill reinstating a ban on assault weapons that lapsed in 2004.