Chris Grayling told MPs it wouldn't be "sensible" to spend taxpayers money on translation facilities but said the government might review the ban if a new MP couldn't speak English.
He was responding to a call from his Labour shadow, Chris Bryant, who suggested MPs could be allowed to speak Welsh during meetings of the Welsh grand committee.
Mr Bryant asked him: "I understand that the language of this House is English but Welsh is the mother tongue of many of my compatriots and constituents so is it not time we allowed Welsh in the Welsh grand committee?"
Mr Grayling replied: "I have given this careful thought. In my judgement, given the fact that English is the language of this House and given the fact it would cost taxpayers' money to make a change at this moment in time, if somebody arrives in this House who cannot speak English we may need to look at this issue again but I think we have considered this issue very carefully and we should retain the situation where English is the language of this House."
MPs have been able to speak Welsh when the Welsh grand committee (made up of all MPs from Wales) has met in Wales and the Welsh affairs select committee (made up of 11 elected MPs) has taken evidence in Welsh at Westminster.
Mr Grayling's comments annoyed Cynon Valley Labour MP Ann Clwyd, who told him: "Can I remind you that some of us took the oath in joining this House in both English and Welsh and I'd ask you to look again at the proposal to use Welsh in the Welsh grand committee? Some of us did not speak English until we were aged five and most of us are now bilingual but nevertheless the Welsh language and its status is very important."
He told her: "Of course I do absolutely understand the need to protect the Welsh language and indeed across different administrations over the last generation extensive steps have been taken to protect the Welsh language, to make it very much a part of routine life in Wales.
"My question to you really is: at a time of financial pressure, is it really sensible for us to be spending taxpayers' money in a House where the prime language, the main language, the official language is English, when we have members of this House who are able to talk in that language? As long as that is the case, I have considered it carefully but I don't believe we should change things."
Discuss.
The leader of the House of Commons has rejected calls from MPs to overturn a ban on speaking Welsh at Westminster.