Six Nations organisers have confirmed the 2021 Championship will take place in February and March as planned in response to suggestions it could be moved to the summer.

The tournament opens when Italy host France on February 6 but, with the Lions' tour to South Africa now in doubt because of the escalating coronavirus pandemic, it had been speculated that the Six Nations could be delayed by four months to take advantage of the potential gap in the window.

With large swathes of the population expected to be vaccinated by the summer, it has been argued there would be scope for crowds to attend, helping financially stricken unions.

But the tournament is set to go ahead in its customary window, unless disruption is caused by Covid-19.

"The Six Nations is planning for the tournament to go ahead as scheduled, but we are monitoring the situation with the unions and their respective governments and health authorities," a spokesperson said.

England expected the launch of their title defence against Scotland at Twickenham on February 6 to proceed as anticipated.

"We are committed to the fixtures and monitoring the situation with all parties. Planning continues aligned with current guidelines," the Rugby Football Union said.

For the Six Nations to be moved to the summer, the Lions' tour would have to be cancelled as soon as possible, but managing director Ben Calveley on Saturday set a deadline of February for a conclusion to the crunch talks over its viability.

Underlining the difficulty facing the Lions on the issue of whether to proceed is Monday's admission by Health Secretary Matt Hancock that he is "very worried" about the South African variant of Covid-19.

The mutation is thought to be more transmissible than the new UK strain and more resistant to the vaccines, resulting in all flights from South Africa to these shores being banned.