Danny Alexander would "relish the challenge" of Alex Salmond standing against him in the general election, he has said.
Salmond, Scotland's outgoing first minister, is rumoured to have his eye on the Inverness, Nairn, and Badenoch constituency, currently held by treasury secretary Alexander.
The gauntlet has now been laid down to Salmond.
On rumour Salmond will run against Danny Alexander in highlands, Alexander says 'people come to retire here,happy to help Salmond with that'
Meanwhile, in Salmond's farewell address to parliament, he dropped a hint that he will stand for Westminster.
Alex Salmond hint? Bows out as Scotland's FM,telling MSPs he has no idea if experience of minority gov may come in useful "in another place"
Alexander won a majority of 8,765 in the 2010 general election, but Salmond's personal popularity, alongside the expected collapse of the Lib Dem vote, would give Alexander cause for concern.
Salmond served as an MP between 1987 and 2010 for Banff and Buchan, and it is expected he would once again take up the position of leader of the Westminster branch of the SNP should he stand and be elected in May.
He will continue to serve as MSP for Aberdeenshire East, regardless of the general election result, with Nicola Sturgeon as first minister.