At the time of the Phoenix League proposal at the start of the century, Celtic and Rangers were very keen, the opposition then was from Premier League clubs - http://news.bbc.co.uk/sport1/hi/football/eng_div_1/1708267.stm
I can recall it all very well, thanks.
Rangers and Celtic were very keen at the time and a proposal was being muted - http://news.bbc.co.uk/sport1/hi/football/1682563.stm
I recall signing a petition against it.