Claire Perry told MPs that she and fellow business minister Margot James would come down on employers who break the law like "a tonne of bricks".
During Women and Equalities questions in the Commons, Ms Perry was asked what steps were being taken to strengthen redundancy protection for new mothers returning from maternity leave by Labour's James Frith (Bury North).
She said: "We know from talking to employers that four out of five say they want to do the right thing and they want to support pregnant women and women returning to work after pregnancy.
"But there are still far too many cases of discrimination and unlawful treatment and both minister Margot James and I are absolutely determined to come down on a tonne of bricks on employers that break the law, and also make sure that women are completely aware of the rights that they currently enjoy."
Mr Frith said he saw "little evidence of the tonne of bricks", and asked Ms Perry if she agreed it was "vital we encourage employers in their legal responsibilities to prevent the discrimination happening in the first place, and that those that don't are held to account?"
Ms Perry said he was "absolutely right", adding that it was women, as well as employers, who needed to be aware of their rights.
"Having had three children, two in America, I can assure members of this House that the rights and responsibilities enjoyed here are far better than other parts of the world, but it is still not good enough and minister Margot James and I are absolutely determined to sort it out."
Former minister Maria Eagle asked about the increase in tribunal fees, which she said were a factor behind women who have been discriminated against not being able to take action.
"Does she not accept that charging a huge fee to take this case to the tribunal is one of the biggest reasons why women who have been discriminated against cannot enforce their rights?"
Ms Perry replied: "(Ms Eagle) will know that there has been an employment fees tribunal, we have found no evidence that indeed pregnancy maternity discrimination is falling foul of the current fee system, but she also knows that we are currently considering responses to the consultation and we will be responding."
Conservative MP Wendy Morton (Aldridge-Brownhills) asked what steps were being taken to ensure "people from all backgrounds can access justice".
Ms Perry replied: "The question I think (Ms Morton) is getting to is has there been a change in access as a result of changes in fees.
"We took very careful consideration of this issue, because it was the case, if you talk to particularly SMEs (small and medium-sized enterprises), that there were very many vexatious tribunal claims being bought, there were, I'm sorry, the honourable lady says 'rubbish' but she should get out and talk to some businesses sometime and hear what they think."
She reiterated there was "no evidence" that maternity discrimination cases had been "particularly affected" by the fee changes .