The head of the Australian Christian Lobby and former special forces soldier Jim Wallace has "unreservedly" apologised for commenting against gay marriage and Muslims on Anzac Day.

Jim Wallace, the managing director of ACL, wrote on Twitter this morning: "Just hope that as we remember Servicemen and women today we remember the Australia they fought for - wasn't gay marriage and Islamic!"

Mr Wallace was heavily criticised on Twitter for his comments.

"What they fought for was freedom from prejudice and persecution. For all Australians!" one user said in reply, while another wrote: "Perhaps you need to remember that many gay servicemen and women also fought and died for Australia."

Mr Wallace later apologised for his tweet, writing that "this was the wrong context to raise these issues".

Mr Wallace said he was spending time with his father when he wrote the first tweet.

"The context of it was that I was sitting there beside my father, who was a 96-year-old veteran of Tobruk and Milne Bay and he was lamenting how he couldn't recognise the Australia he fought for.

"And my ill-timed Twitter was just reflecting the nature of Australia that people fought for is different and I think it's being redefined all the time."

Christian leader sorry for Anzac tweets

What kind of low-life, mealy-mouthed hypocrite would seek to justify his behaviour by dragging his 96 year-old father into the situation .... Wallace may be a former member of the SAS but my Uncles, both of whom fought in Tobruk & on the Kokoda Trail, would view his actions as an act of cowardice.

Wallace doesn't bother to elaborate on the 'kind' of awstrayla that his poor father was thinking about but, if he is anything like my kin, he would lament the fact that our crooked, self-righteous politicians continue to send our nation's youth to fight as proxies for foreign criminals & their rapacious colonialist enterprises; that the same hypocritical politicians continue to try & conceal their evil ways behind a flag woven of jingoism, nationalism, fear & bigotry; that the same mean-spirited 'representatives of the people' do everything in their power to avoid ensuring adequate support & compensation is awarded to those who are injured or make the 'ultimate sacrifice'.

Or maybe it's a case of like father, like son, & Wallace senior pines for a 'white awstrayla', when women were for rooting, having kids & doing housework & anyone whose sexuality wasn't hetro would be obliged to hide-out in a public toilet; perhaps become a military officer or join the ministry? Those were the days: no need to worry about towelheads when you couldn't get into this country unless you were a white anglo-celt; to work in some government departments, you needed to be a catholic or a mason.

One thing that Wallace senior would be familiar with, that has never gone away, is our propensity for racism & bigotry. That people like his 'christian son' think that this is what they fought for simply demonstrates what a senseless waste war really is.