They have said taking the Edinburgh to Tweedbank line on to Carlisle should be a key post-coronavirus project.
The Campaign for Borders Rail added that, despite more home working under lockdown, the capacity and coverage of the rail network needed to grow.
Simon Walton, who chairs the group, said such investment was vital if there was to be a "meaningful recovery".
The rail line between the Scottish capital and the Borders opened nearly five years ago.
The CBR saw that as a partial victory but has since lobbied to see the route extended across the border into England.
One part of the multi-million pound Borderlands Growth Deal for southern Scotland and northern England is a study to look at taking the line to Carlisle.
Mr Walton said he believed that after the current cycle of "isolation and immobility" the scheme would have even greater value.
"Bringing communities together, making it more possible to communicate with each other, will be even more important," he said.
"Better connecting the Borders to each other, and to those communities around us, will be recognised for its true worth."
He added that the extension could also help bring people together - a key part of any recovery.
"Our movements may be restricted - for now - but our ambition remains unbounded," he said.
"We do of course keep up our efforts remotely.
"When the time is right, and it is safe to do so, we will be re-engaging with decision makers, and progressing the campaign."
Campaigners seeking to extend the Borders Railway have said the scheme is "more important now than ever".