Speculation is mounting David Cameron is planning to install more leading Tory women into the most senior positions in a shake-up before Parliament breaks for the summer.
But shadow home secretary Yvette Cooper accused the prime minister of having a "real blind spot" over women and said it would be "too little, too late".
She told Murnaghan on Sky News: "I think if he was serious about having women in his Cabinet, he's had four years to do so.
"There's only three women in the Cabinet at the moment and I think this is going to look really like a last minute worry about votes because he knows that he's got a real blind spot when it comes to women."
Home Office minister James Brokenshire insisted the prime minister "absolutely" does not have a blind spot when it comes to women.
"As a male minister in the government, I look at the talented people that we have - men and women - and I think we are a very well-balanced government," he told Murnaghan.
"I think it is looking at the talent that we have, but yes we need to do more to ensure that as a party we reflect men, women and also all communities across the UK."
Meanwhile, Liberal Democrat Justice Minister Simon Hughes said party leader, deputy prime minister Nick Clegg, was "mindful" of getting more women into Government and the Cabinet.
Mr Hughes told the programme: "I haven't a clue (about a LibDem reshuffle) because in the end each of the two party leaders makes their own dispositions.
"Obviously Nick Clegg as deputy prime minister is entitled to reshuffle his team whenever he wants to within the agreement between the two parties.
"And he's absolutely mindful of making sure that we have more women in government - the fact that we have people like Jo Swinson firing on all cylinders is very welcome in the party."