Attorney-General George Brandis has sought to quell free speech concerns about the government's national security reforms by giving himself the power to veto prosecutions of journalists who publish details of undercover ASIO operations.

The decision follows a growing backlash against a law passed more than a month ago that includes jail terms of up to 10 years for anyone who discloses details about ASIO "special operations", during which the security agency's officers would have partial legal immunity in the event they have to break the law in the course of their work.

Gatekeeper: Attorney-General George Brandis Credit:Andrew Meares

Amid concerns that the law could prevent journalists reporting on, say, botched special operations, Opposition Leader Bill Shorten wrote to Prime Minister Tony Abbott on Thursday asking that an independent watchdog on national security laws review the clause by the middle of next year.