Carson City Council (CCC) in Los Angeles County, California, US has unanimously approved plans to build a US$1.86bn (€1.68bn, £1.24bn) stadium to host two National Football League (NFL) franchises – the San Diego Chargers and Oakland Raiders.

CCC is the second local authority to have given a green light to an NFL stadium in Los Angeles, following a rival plan by billionaire Stan Kroenke to relocate his St Louis Rams NFL franchise to a HKS-designed venue in Hollywood Park in Inglewood.

Both plans were presented to a committee of NFL executives on Wednesday 22 April. To approve any relocation of a franchise, NFL rules require that 75 percent of the 32 owners approve the move.

In a joint statement, the Chargers and Raiders said the plans to relocate both teams to a joint, 70,000-capacity stadium designed by architects Manica, follows unsuccessful searches for new stadiums in their home markets.

“We’re pursuing the stadium option in Carson for one straightforward reason: if we cannot find a permanent solution in our home markets, we have no alternative but to preserve other options to guarantee the future economic viability of our franchises,” the statement said.

Average attendances at Chargers games declined steadily between 2008 and 2012 – from 68,138 to 59,964 – while attendances at Raiders games have consistently been among the lowest in the NFL.

Raiders’ current home stadium, the O.co Coliseum, has a capacity of 56,057 while the Chargers’ Qualcomm Stadium can hold 70,561 fans.