Jeremy Corbyn has proposed a tightening of Labour rules and launched an independent review into racism as he seeks to calm tensions in the party over alleged anti-Semitism in the ranks.
A code of conduct would "make explicitly clear for the first time that Labour will not tolerate any form of racism, including anti-Semitism, in the party" and provide guidance on acceptable language.
Former Liberty director Shami Chakrabarti has been appointed to head a panel tasked with drawing up "a statement of principles and guidance about anti-Semitism and other forms of racism".
The panel - whose vice-chairman is Professor David Feldman, director of the Pears Institute for the Study of Anti-Semitism - is expected to consult with the Jewish community and other minorities and report within two months on issues such as "transparent compliance procedures" and training.
Mr Corbyn insists there is no "crisis" within the party but his handling of anti-Semitism allegations, which have led to the suspension of long-time ally Ken Livingstone and Bradford West MP Naz Shah, has been criticised.
Announcing the attempted fightback, he said he had taken "decisive" action.
"We have taken decisive action over allegations of anti-Semitism since I became leader, suspending all those involved from membership, and have set up an inquiry under Baroness Royall into reports of anti-semitism in the Oxford University Labour club and elsewhere.
"There is no place for anti-Semitism or any form of racism in the Labour Party, or anywhere in society. We will make sure that our party is a welcoming home to members of all minority communities."
It came as an unrepentant Mr Livingstone suggested Labour will have to lift his suspension over controversial remarks linking Adolf Hitler to Zionism as the row over the party's handling of anti-Semitism allegations continued.
The former London mayor's comments were branded "vile, offensive and crass" by the party's deputy leader, Tom Watson, who said Mr Livingstone had "let down the Labour Party".
But the former London mayor, who faces calls to be expelled over his remarks, claimed that the party's internal inquiry would have to let him back in because "it's hard for somebody to decide to suspend me from the party" when he had been making the same point for 30 years.
The recommendations of the inquiry led by Baroness Royall are expected to feed into the wider inquiry.