Plymouth Argyle and the Cornish Pirates have agreed to a temporary groundshare deal, should the Pirates get promoted to rugby's Premiership next season.
It would come into force if a proposed new stadium for Cornwall is not finished for the start of the season.
The deal must also be ratified by rugby's Professional Game Board and Argyle's fixtures would take priority.
It also relies on the Pirates paying compensation to Plymouth Albion if they are affected by the plans.
Among the Premiership's rules on grounds is a minimum capacity of 10,000.
"If the Pirates win promotion to the Premiership, Argyle would be delighted, in principle, to host them on a temporary basis," said Argyle's chairman of football operations Peter Ridsdale.
"It is important, however, that the terms of any deal are not only fair to Argyle - and through the club, to its employees, past and present, who would receive part of the unbudgeted income - but also protect the interests of our friends at Albion.
"If the stadium goes ahead and if the Pirates win promotion, this is good news for sport in Devon and Cornwall, and we wish them every success."
Pirates chief executive Rod Coward said he was talking with Championship club Plymouth Albion about ensuring they do not lose out.
On Thursday Albion's chairman of rugby, Graham Dawe, said he was against a lengthy groundshare between the two clubs.
"Discussions are taking place with Plymouth Albion to reach agreement on a compensation package," Coward said.