Microsoft-backed lobby group ICOMP's long-running fight against Google's search dominance in the European Union has collapsed amid accusations that its members have been silenced.

Ars has learned that members including UK-based price comparison site Foundem—the original complainant in the antitrust case against Google—resigned from ICOMP after Microsoft backed away from what had been a dogged campaign against its search rival in Europe. ICOMP was founded in 2008 to fight for an "online competitive marketplace."

One source told us that Microsoft had agreed to prop up ICOMP's food, travel, and accommodation expenses without having any active involvement in the group.

In a letter from Foundem to ICOMP—seen by Ars—the company said: "In our view, an ICOMP that is prohibited from commenting on Google’s immensely damaging business practices is an ICOMP working against, rather than for, the interests of a fair, competitive online marketplace."

Foundem added in its December 2 missive: "As a leading complainant in the European Commission’s ongoing competition investigation into Google’s search manipulation practices, Foundem cannot be a member of an organisation that has turned its back on such an important issue.”

Ars asked Microsoft to comment on this issue to confirm claims that its fight against Google on search in the EU was effectively over. It did not respond directly to that question, however. Instead we were told that Microsoft's complaint against Google in the European Commission had not been withdrawn.

In January, when Ars made a routine inquiry about Microsoft's battle with Google's search dominance in the EU, a spokesman confirmed that the software giant's lobbying had abated. We were told at the time that the case had moved on, given that the European Commission—under competition chief Margrethe Vestager—had issued its Statement of Objections against Google.

Foundem, which first filed its antitrust complaint with competition officials in Brussels in 2010—leading to a formal probe being opened in the EC in November of that year—declined to comment on this story.

An ICOMP spokesman said: “While we continue to monitor the investigation, we are aligning our focus to evolving interests of our membership—who are fully disclosed on our website. There is no change of status to ICOMP’s complaint.”