UK Culture Minister Ed Vaizey says the UK government is "committed to Welsh programming and committed to S4C".
In a Westminster Hall debate, Mr Vaizey outlined what he called a "very generous funding settlement" for the Welsh language channel.
He said S4C would receive £90m in 2011-12 and would still be receiving £83m in 2014-15.
It was announced on Tuesday that responsibility for S4C's funding would be transferred to the BBC from 2014.
S4C is seeking a judicial review over the decision.
In the debate, Conservative MP for Aberconwy, Guto Bebb, said that a cut to S4C's funding could be justified "as long as it is in line with cuts in the rest of the department".
He said that 20% was manageable but that anything more would be "problematic" and said he would not accept anything more than 25%.
Mr Vaizey said S4C had a "very bright future" and emphasised the UK government's support for Welsh-language programming.
He confirmed the S4C budget in 2011-12 would be £90m "to add to the £3m that it gets from commercial revenues and the £27m it has in reserves".
This would be in addition to the "£20m of programming it gets from the BBC", he said.
He added that by 2014-15 its budget would be £83m.
He also said he expected 100% of the content budget to be spent on the independent sector.
"I have enough faith in the people of Wales to think that they will look at those figures and think those are generous funding figures," he added.
Mr Vaizey insisted the editorial independence of S4C would be guaranteed.
He also gave assurances the BBC would not be able to "siphon off" money for promoting BBC channels.
Responding to accusations that Westminster had shown "contempt" to Wales, Mr Vaizey said: "We are not the London government, we are the government of the United Kingdom and we have to make decisions with the interests of not only the Welsh people at their heart but also that of the people of the United Kingdom."