A former City minister under Gordon Brown has disclosed he made a "significant" donation to the newly-formed Independent Group.
Lord Myners, an ex-chairman of Marks and Spencer, said "most of the population don't live at the extremes" and praised the group for gathering together a broad range of voices.
The Independent Group (TIG) sent shockwaves through Westminster when they formed last month, after a string of Tory and Labour MPs quit their parties in protest at the direction each was headed.
The group is not yet registered as an official party, so it does not have to declare its donations, but Lord Myners revealed that he had made a major gift to support the TIG MPs.
The crossbench peer told BBC Radio Cornwall: "I’ve given a significant amount of money. They’re not even at this stage a political party.
"I don’t know how they’ll approach future elections but I like the idea of a party which brings together people like Chris Leslie and Chuka Umunna from the Labour Party and Heidi Allen and Anna Soubry and the wonderful Dr [Sarah] Wollaston from Totnes from the Conservatives into a single group.
“That’s where I believe a lot of us actually live in that middle, in the bell shaped distribution. Most of the population don’t live at the extremes.
"We’re not ardent right wing or ardent left wing, most of us are in the middle area and yet somehow we’ve lost our voice.”
Former Labour MP Chuka Umunna, who acts as a TIG spokesman, has confirmed that the group is in talks with the Electoral Commission about becoming a fully fledge political party.
He said the group was "absolutely overwhelmed by the tens of thousands of people who have signed up to our website, who have shown support for what we are doing".
The collective is currently run through a private company, of which TIG MP Gavin Shuker is listed as a director.