GRENOBLE/PARIS--President Nicolas Sarkozy proposed tough measures on Friday to fight crime, delinquency and illegal immigration as he looks to shore up his support amid scandals and low ratings ahead of 2012 elections. Speaking in France's southeastern city of Grenoble, the scene of riots two weeks ago sparked by the death of a man of Arab origin who was fleeing the police, Sarkozy partly blamed immigration for a breakdown in society. "We are suffering from 50 years of lax immigration regulation which has led to a failure of integration," he said in a defiant speech. Sarkozy, whose "tough on crime" stance helped him win the 2007 election, has promised to "wage war" on urban violence following the riots, a move critics say is partly aimed at winning back right-wing voters. The National Front, severely squeezed by Sarkozy in 2007, has regained some support due to the economic crisis which has raised unemployment to 10 percent and several political scandals that have fed its accusations of a corrupt establishment. "French nationality should be stripped from anybody who has threatened the life of a police officer or anybody involved in public policing," Sarkozy said. "Nationality is earned and you have to be worthy of it." Police in the Grenoble area have received death threats since the riots. Sarkozy proposed a string of measures including sentences of up to 30 years for killing police, convicted criminals wearing electronic tags after release and a review of underage offenders of foreign origin receiving nationality at 18. A furore over alleged illegal political donations and tax evasion by France's richest woman has dogged his government and sent Sarkozy's approval ratings to all-time lows. His centre-right UMP party lost an ultra-safe parliamentary seat in a by-election this month, highlighting anger at the scandals and an unpopular planned pension reform. He has announced a cabinet reshuffle for October, which is likely to ditch members lured from the left and bring in trusted conservatives to see him through the 2012 presidential vote. Sarkozy's government already faces criticism for pushing through a ban on wearing a full veil in public, which opponents say discriminates against Muslims and creates a climate of suspicion and hostility towards immigrant communities. He said he was unconcerned by those who said his measures were an attack on civil liberties. "There is no stigmatisation, this is in the general interest for everybody. Values are disappearing and we have to stop this," he said.