MPs are debating the government's controversial repeal bill which aims to transpose EU rules and regulations into the domestic law books ahead of Brexit.
Maria Miller, Bob Neill and Bernard Jenkin, as well as Labour's Frank Field, all of whom chair select committees that support the European Union (Withdrawal) Bill, said they expect amendments will be necessary if the bill is to become law.
Ms Miller, chairwoman of the Women and Equalities Committee, said an amendment was needed to "explicitly commit to maintaining current levels of equality protection".
Nonetheless, she backed the bill at its second reading, saying it would allow the government to "get on with the job" of exiting the EU.
Labour leader Jeremy Corbyn has called on all Labour MPs to follow him in voting down the bill, but Ms Miller warned Labour's plan to vote against it could be seen as a "blatant attempt to frustrate" the Brexit process.
"There are strong arguments that this bill needs amending, but none that say this bill is unnecessary," she said.
The EU (Withdrawal) Bill ends the supremacy of EU law in the UK and converts all existing EU law into domestic legislation.
But ministers believe between 800 and 1,000 such statutory instruments will be required as Brexit legislation makes its way through parliament.
Mr Field, who is chairman of the work and pensions committee, warned the government was "storing up no end of trouble" by having such a "mega bill".
Opposition to the bill stems from the so-called "Henry VIII powers" the bill gives to ministers to alter laws without full parliamentary scrutiny, with some labeling it a "power grab" by the government.