Rangers' non-executive directors, John Greig and John McClelland, have resigned from their posts at Ibrox.
The duo say that they have been isolated following Craig Whyte's takeover of the club in May.
"These resignations have been communicated by letter to the chairman, Craig Whyte," read a statement.
"Both were of the opinion that since the change of ownership they have been excluded from participating in corporate governance at the club."
Greig captained Rangers during his playing days in the 1960s and 1970s, leading them to victory in the final of the European Cup Winners Cup in 1972.
The 69-year-old, who won 44 caps for Scotland, also managed Rangers between 1978 and 1983.
McClelland was chairman of the club between 2002 and 2004.
The resignations come one week after Rangers finance director Donald McIntyre officially stepped down from his role, although he remains an employee.
And the Rangers Supporters Trust expressed concerns over the latest departures.
"We regret the resignation of John Greig and John McClelland from the club board," said acting chairman Gordon Dinnie in a statement.
"One is a club legend, the other is one of Scotland's most distinguished businessmen.
"We're greatly concerned that these resignations raise issues of governance and transparency within the Rangers board.
"It's important that the club moves quickly to appoint replacements and the chairman should be looking at candidates who have a credible Rangers background and relevant business experience."
McIntyre and former chief executive Martin Bain were both suspended by the Scottish champions in May, shortly after Whyte completed his takeover.
McClelland and Greig survived that initial boardroom overhaul, but their decisions to leave add to a growing list of off-field problems for Rangers.
The Scottish champions, who lead Motherwell by seven points at the top of the Scottish Premier League, are currently involved in two separate tax disputes with HM Revenue and Customs, while Bain is also suing the club for £1.3m in an unfair dismissal claim.
Last month, Bain had £480,000 of the club's assets frozen after a judge agreed there was "real and substantial risk of insolvency".
McIntyre has since launched a legal bid to ring-fence £300,000 of the club's money pending a breach of contract case.
A spokeswoman for Rangers said the club had accepted the resignations of Greig and McClelland but refused to comment further.
The pair were on the independent board committee, which delayed Whyte's buyout and then expressed concern over "a lack of clarity" over the new owner's financial muscle, hours after he had completed his buyout of Sir David Murray's shareholding on 6 May.
The committee was led by chairman Alistair Johnston, who was removed from the board later in May, along with Paul Murray, who had launched a late rival takeover deal.