The Department of Education has been finalising details in its planning document before it is brought to Cabinet on Monday.
The Government said its priority is to see the full reopening of schools at the end of August.
Mr Varadkar told RTE’s the Week in Politics programme on Sunday that he has read the comprehensive document in recent days and is “confident” students and teachers will return by the end of next month.
He said: “The Government’s plan is ready, it’s going to go to Cabinet tomorrow.
“It involves a really big investment in changes to schools and school buildings.
“It involves extra teachers, it involves cleaning regimes, and involves all sorts of practices and procedures that may occur if there is a case of coronavirus in schools.
“And also special arrangements for teachers who have a chronic illness, for example. A lot of work has gone into it. There has been a lot of consultations with the unions.”
Sinn Fein TD Pearse Doherty said that his party has not been given sight of the plan that had been promised by the current and former education ministers.
“We were told that we would have a plan by June 12, it didn’t materialise,” Mr Doherty said.
“We need to get this right and I say that, not only as a public representative, but as a father of four children who doesn’t know how they are going back to school safely. We need this plan to work. They have put it right down to the wire now so there is very little wriggle-room if there is issues.
“We knew there would be need for additional resources, in terms of teachers, SNAs. There is limited time for us to hire those.”
Labour’s education spokesman Aodhan O Riordain said that now is the time to permanently reduce class sizes.
He said: “With details finally starting to emerge about school reopening plans the Government must seize the opportunity to permanently reduce class sizes and ensure a generation of young people at risk are not left behind.
“The reopening of our schools is quite simply the most important item on the Government’s agenda. Nothing can go back to normal in September unless the schools are back.
“Schools will need extra staff, extra building capacity and of course resources available to clean and sanitise their classrooms on a regular basis.”
On Sunday the Department of Health confirmed that there have been no further deaths from Covid-19 in the last 24 hours.
The health system has been notified of another 12 confirmed Covid-19 cases.
Mr Varadkar also admitted plans to monitor people travelling into Ireland from countries that are not on the “green list” needs to “tighten up”.
He said: “We’re going to look at other measures as well, for example, the possibility of requiring people to have evidence of a negative (Covid) test prior to travelling from some countries.”
He raised concern that holidaymakers from Northern Ireland are allowed to travel to 59 countries without having to quarantine on their return, while the Republic’s “green list” features just 15 nations.
Earlier this week Stormont’s health minister Robin Swann asked his cross-border counterpart to consider new laws and data-sharing agreements to help track international travellers arriving on the island.
But Mr Varadkar said the Northern Ireland Executive has been “very clear” it does not want to have an all-island approach to its travel arrangements.
He said it will be one of the issues discussed at this week’s North-South Ministerial Council meeting in Dublin.
He added: “Certainly in any conversations that I had with the First Minister (Arlene Foster) and anything she said since, they’ve been very clear that when it comes to travel they want to stick with the common travel area with Britain and won’t be restricting travel between Britain and Northern Ireland.”
Meanwhile, Finance Minister Paschal Donohoe has again moved to defend the Government’s decision not to cut the tourism VAT rate, despite persistent calls from businesses in the hospitality sector.
The Government last week unveiled a seven billion euro plan to stimulate the economy.
Mr Donohoe said cutting the standard rate of VAT from 23% to 21% will impact on more businesses and consumers.
However, a number of firms said this will not stimulate more demand for business
Mr Donohoe said: “I think the thing that is most likely to cause an acceleration of the return of consumer confidence later on in the year is where we are with our public health, is where we are with our skills, and is where we are with getting employers and people confident to be back in offices later on in the year and next year.
“It is the case that we have many retailers that continue to be very profitable, and in some cases this profitability has been enhanced because of what happened with shopping patterns during the earlier phase of this disease. For those retailers that are very profitable, I absolutely want to see the VAT reductions to be passed on.”
Mr Donohoe told Newstalk some retailers will face a choice between implementing a price cut or using the VAT reduction to maintain their employees.
