Gavin Shuker has told the BBC's Newsnight programme claims from the Muslim Women's Network UK (MWN) of "systematic misogyny" by some Labour Muslim male councillors are true.
The Labour representative for South Luton said he was "disapointed" by Labour's response to the concerns and added: "In recent weeks, when I've spoken up about this issue, I felt extremely pressured to be silent on the things I know to be true."
In a letter addressed to Labour leader Jeremy Corbyn last month, the MWN claimed "nepotism and cronyism" were among tactics which have been used to undermine, sabotage and block Muslim women from becoming local councillors.
The Labour Party said: "We have transformed the representation of women in politics and championed equality for women in the workplace.
"Any complaints or evidence of sexism, intimidation, received by the Labour Party are dealt with fairly, according to our procedures and the law.
"Labour Party elected representatives are expected to maintain the highest standards of behaviour and conduct at all times.
"Any allegations of individual elected representatives whose behaviour falls short of that should be reported to the Labour Party or the appropriate authorities."