The Coalition will announce tomorrow a new water charges package, now expected to see bills as low as roughly €60 for a one-person household and €160 for all others.
Under the new plans, the Government is also postponing the start date for billing by three months - with the first bills not due until April.
Gardai are also considering assigning armed officers to ministers as water protests become increasingly hostile.
A beefing up of protection measures for Government members was ordered after Tanaiste Joan Burton was trapped by protesters, in an incident which Taoiseach Enda Kenny says amounted "almost to kidnapping".
The review of security comes as protests continued to become more heated across the country.
Mr Kenny was also caught up in the drama when his car was surrounded by more than 300 angry protesters as he arrived at a Fine Gael party meeting in Sligo last night.
Security sources say gardai are now planning:
• threat assessments of every event attended by ministers;
• a review of security at the homes of ministers;
• investigation of incidents.
A major security review was ordered by the Acting Garda Commissioner Noirin O'Sullivan after a bomb threat was made yesterday to the constituency office of Environment Minister Alan Kelly, who is responsible for water charges, in Nenagh, Co Tipperary.
A number of ministers may be assigned armed garda drivers as an "interim" measure as part of the overall review, security sources have revealed.
When the Coalition came to power in 2011, garda drivers were withdrawn from Government members with the exception of the Taoiseach, Tanaiste, Justice Minister and Attorney General.
Senior gardai will now also conduct advance "threat assessments" prior to all public engagements where Government ministers are scheduled to attend.
A much larger garda presence will be allocated to such venues, with public order units on standby.
Several garda units, including the Crime and Security branch and anti-terrorist Special Detective Unit, are also involved in compiling intelligence on "rogue" protesters.
Security at the private homes of senior Government personnel is also likely to be re-assessed by local garda management as the protesters, including criminals and Republican sympathisers, appear intent on increasing their campaign of intimidation and threats.
The Garda National Bureau of Criminal Investigation (NBCI) is to investigate the circumstances of the Tallaght protest on Saturday. Detectives will interview the Tanaiste, her staff and other witnesses as well as gardai who were on duty to establish if crimes were committed by individual protesters.
Officers will also examine all footage from the protest which was uploaded to the internet. It is understood that some of the protesters may face charges under public order and offences against the person legislation.
A senior security source told the Irish Independent last night: "We have seen a steady ratcheting up of the violence and aggro from a coterie of people with connections to various Republican groups and criminals.
"Intelligence sources have revealed this hard core of people are intent on causing as much chaos as possible and are trying to push confrontations such as the one in Tallaght so that people are injured or worse," the source added.
"A number of gardai have also been injured and all anyone has to do is watch some of the clips on YouTube to see how these people are blatantly trying to provoke confrontation.
"They have even uploaded clips of individual gardai asking people to identify them and where they live. This is ugly intimidation and threat at its worst and it is getting out of hand," the source added.
A garda spokesman refused to comment on the ongoing review, saying they don't discuss "sensitive, individual security situations".
Government sources confirmed the incident involving the Tanaiste at the weekend meant security had to be reviewed. "You have to be cautious with any changes because this is what these fellas want," a source said.
The Cabinet will hold a meeting tomorrow to sign off on the water charges package.
It had been planned to begin charging for water from last month, with the first bills arriving in January. But now the first bills will arrive in April instead, covering January, February and March.
We live in a country where ordinary citizens have always enjoyed access to their senior politicians. Right the way up to the Taoiseach, the constituency clinic is a tradition in politics that allows everyone to draw the attention of their TD to whatever issue is on their mind.