The position of the Leader of the Opposition was formally recognised in the Salaries and Allowances of Leaders of Opposition Act, 1977. However, de facto recognition and conventions surrounding the role were established earlier, with significant developments in 1969 when the rules for its recognition were formalized. The requirement for a party to secure at least 10% of the total seats (which approximates to 55 seats in the current Lok Sabha of 543 members, and would have been around 50 in the first Lok Sabha) is a key criterion for its leader to be officially recognised as the Leader of the Opposition.