Former taoiseach Bertie Ahern has said he has "no desire to see the backstop ever implemented" in the event of a no-deal Brexit.
But he said the arrangement was necessary to ensure there was no return to a hard border on the island of Ireland.
Mr Ahern was giving evidence to the House of Commons Committee for Exiting the European Union in London.
He said the backstop was an insurance mechanism to ensure the border stayed open, and that technological solutions to avoid a hard border are not in existence today, although they might be in the future.
"It seems to me that in the transition period it must be possible to work out an arrangement and work out a way that means that the backstop isn't necessary but that needs time and, as of now, all of the brain power said that this (the backstop) is what we should do."
Mr Ahern said he believes it is the view of many in Ireland that some infrastructure will appear on the border if there is no deal on Brexit.
He said the current Withdrawal Agreement agreed between the UK and the EU was the best way to address the many issues that arise such as cross-border trade.
He said a no-deal Brexit would be devastating to small, indigenous employment in Ireland as smaller family farms and local employers would be particularly hard hit, with estimates of a possible 40,000 job losses in Ireland.
Mr Ahern also said suggestions the Republic of Ireland leave the European Union or rejoin the UK have "not gone down very well" in Ireland.
"A lot of people have put a lot of time into developing a new relationship between the UK and Ireland and unfortunately we have an 800 year past of difficulties."
Mr Ahern said if the British government decides, for whatever reason, that more time is needed to agree its departure from the European Union he could not see why that would be rejected.
He said the Good Friday Agreement is of paramount importance in the Brexit negotiations in relation to parity of esteem and constitutionality clauses.
He said the language must pass the test of Article 1.5 in the agreement as Northern Ireland was not the same as any other part of the UK.
In relation to a border poll, Mr Ahern said it would be very irresponsible to look at holding one now or in the near future.
He said he wanted to see Brexit happen first and to have the institutions in Northern Ireland back up and running.
"Bringing a border poll into the middle of this in my view is irresponsible"
The DUPs Sammy Wilson asked Mr Ahern if he thought Taoiseach Leo Varadkar's rhetoric recently in relation "to turning out the lights" in Northern Ireland, sending troops to the border and "a Berlin Wall around Northern Ireland", was helpful, to which Mr Ahern replied: "Rhetoric from anybody at this time isn't helpful".
Some views expressed in UK 'factually incorrect'
Speaking to RTÉ News after the committee hearing, Mr Ahern said that when you are on the sidelines of the Brexit debate you know that some of the views expressed in the UK are factually incorrect.
He said that anyone who thinks that Brexit does not impact on the Good Friday Agreement is wrong.
Belfast, he said, is not the same as Finchley and he said he made that point to MPs today as it is important they understand that.
The former taoiseach said that from talking to MPs afterwards it was clear that many do not read the Good Friday Agreement very often, and he hoped that might now change.
Mr Ahern said he was concerned about a no-deal Brexit and he was aware of the heightened concerns around that, but he remains hopeful that a deal can be reached.