Science and secular government
I see we're playing hobby-horse bingo and we've hit the jackpot!
Anyway, enough of the mixed metaphors. I'd like to take a wild guess that the MPs were not trying to put an end to the creationist/evolutionist debate, but are thinking more along the lines of "we need physicists/chemists to develop new semi-conductor type materials for IT", vs the government's "oops we spent all the taxpayer's money on a stupid war", dilemma. No religious content here, move along, nothing to see.
Regarding secular government, I don't think there is a presumed secularity. It may come as a shock and be rather offensive, but MPs and government are supposed to represent those who elected them, not just the secular humanists.
It isn't belief in a God that causes wars, its the arrogant pride that my way is the only way and therefore I'm going to force my opinions and way of doing things on everyone else.
Toleration is about being civil with those with whom you fundamentally disagree. The increase in secularity in society appears to have very little to help this. Seeing talk of depriving people of the right to participate in government based on their religious beliefs, it appears that you can change the religious labels, but people really haven't changed since the 16th century.