One Fine Gael minister who is vehemently opposed to entering into government with Fianna Fáil has an interesting analogy for explaining his position.
He compares the potential coalition to two rival newspapers merging and printing the exact same content in their separate titles. The front pages and layouts might be different but it's the same news, analysis and features from the same writers inside.
He says readers will eventually question the need for the two papers and shops will only stock one of the titles. What's the need for two products that provide the same service?
The minister says the same will happen to Fine Gael and Fianna Fáil.
If the coalition goes ahead, voters won't be able to differentiate between the two parties. When an election is called Fine Gael candidates won't be able to distinguish themselves from their rivals in Fianna Fáil after sharing power for five years.
Politics is a service and for decades Fianna Fáil and Fine Gael have been the main providers. They are the Pepsi and Coca-Cola of Irish politics - two similar products with their own unique identity and following.
There are historical and ideological differences but they are both driven by the desire which is to convince enough people to vote them into power. Policies and stances shift over time to meet electoral demands.
Right now, if voters were asked to do the political equivalent of the 'Pepsi challenge' they might struggle to tell the difference.
Over the past four years they have been edging closer together. The confidence and supply agreement showed the public they could do business together in the Dáil.
They were able to put aside their supposed differences for the good of the country for three years before extending the deal for another year to provide stability during Brexit.
Three weeks ago they went public with their relationship following the publication of their policy framework document.
After years of rumour and innuendo, finally Fianna Fáil and Fine Gael admitted publicly they were willing to get into bed with each other. Which brings us back to branding and identity. Politics, just like fizzy drinks, is all about marketing.
Millions of euro are spent by political parties on research and opinion polls to convince you to put a number one beside their party logo when you are marking your ballot paper.
If the last General Election is anything to go by, Fianna Fáil and Fine Gael's brands and identities have been damaged by doing business with each other.
Yesterday's 'Business Post'/Red C opinion poll also showed that the closer the two parties come together the more damage it does to Fianna Fáil.
Nationally, Micheál Martin's party is at 14pc, while in Dublin it is at a mere 8pc. Martin has been working tirelessly to form a government in recent weeks but he is getting no thanks for his efforts.
Leo Varadkar, meanwhile, is enjoying a Fine Gael renaissance as is the case in most countries where leaders are polling strongly with the public as they tackle the coronavirus.
Fine Gael is at 35pc - some 14 points higher than its General Election result. Sinn Féin is still performing well on 27pc.
It's very unlikely this is how another election would play out, but it is nonetheless very worrying for Fianna Fáil to see support drop further the more entwined it becomes with Fine Gael.
Even more concerning is the fact the party doesn't get rewarded for facilitating Fine Gael's government during the good or bad times.
Fianna Fáil members must also now be wondering if their identity will be erased entirely if they end up in government with Fine Gael.