Many have called it an insignificant economic agreement while in practice, everything that PA leader Mahmoud Abbas has insisted upon - one government with one weapons arsenal - did not materialize and the Hamas terrorist organization's so-called military branch has not yet disarmed itself.
If this deal succeeds, the Palestinian territories of the West Bank and Gaza will be reunited under one leadership for the first time since the Islamist militant group Hamas wrested control of the territory 10 years ago.
And he said a reconciliation deal makes peace harder to achieve. But instead, the global community should have tried to "pull Hamas into a dialogue", Blair said in an interview for Donald Macintyre's "Gaza: Preparing for Dawn", which is set to be released in November.
This comes after the two factions signed a reconciliation agreement in Cairo last week, including a timetable for elections, and the transfer of Gaza border crossings to Palestinian Authority control.More news: 'Carpool Karaoke' episode with Linkin Park frontman Chester Bennington released
The crossing has remained largely closed in recent years.
Although Mr Blair did not elaborate on the nature of the British Government's "informal" contact with Hamas, he appeared to be referring to talks between MI6 and Hamas representatives to secure the release of a British journalist kidnapped in Gaza in 2007.
Also as part of the agreement, the Palestinian Authority can not take any new steps regarding Israel.
Senior Hamas leader Saleh al-Arouri (left) sits next to Fatah's Azzam al-Ahmad as they sign a reconciliation deal in Cairo on Thursday.More news: Election Commission announces dates for Assembly elections in Gujarat, Himachal Pradesh
It has fought three wars with Israel since 2008 and the blockaded Gaza Strip has seen deteriorating humanitarian conditions.
"Hamas may be willing to cede more administrative control of Gaza", he said, "but the parties have so far avoided the issues likeliest to derail the talks: namely, the relationship with Israel and what to do with Hamas's military wing", he was quoted by the New York Times as saying.
In an interview with The Observer, the former Prime Minister said: "In retrospect I think we should have, right at the very beginning, tried to pull [Hamas] into a dialogue and shifted their positions". Among the sanctions was the Palestinian's decision to not pay Israel for electricity provided to Gaza, leading to a serious cut in the number of hours a day that electricity is available.More news: What USC QB Jake Bentley did following Saturday's win has people talking
- Trump to announce Iran strategy tomorrow: White House
- German Football Team distracts from losses by kneeling down
- Need Something From Target? Ask Google Assistant
- Brexit: UK and European Union 'move heaven and earth' to protect NI
- Flight 666 to HEL on Friday the 13th Arrives Safely
- Mother of Eight Among Three Dead in Tragic Skydiving Accident
- Oculus details inside-out tracking of Santa Cruz prototype headset
- Congress blazes victory trail in Nanded, BJP trails (2nd Lead)
- Honor 6C Pro unveiled with modest specs and sleek design
- Court Rules in Favor of National Football League in Ezekiel Elliott Suspension