PORTLAND, Maine (NEWS CENTER) -- Maine Senator Susan Collins ended weeks of speculation Friday afternoon and announced she will vote in favor of the controversial Senate Republican tax plan.

Collins had expressed strong reservations about the plan, but was able to win concessions on several issues and have changes made to the plan.

RELATED: Read Collins' full statement on the tax bill

The Senate accepted three of Collins' four amendments. One allows tax filers to deduct the amount of local property taxes they pay, up to $10,000. Another allows taxpayers to deduct medical expenses if they exceed 7.5% of annual income.

Collins's other primary concern had been the Senate Republican plan to repeal the individual mandate for health insurance, a key portion of the Affordable Care Act. Critics have said the repeal would make policies unaffordable for millions of Americans. In a written statement, Collins said Senate Majority Leader Mitch McConnell had pledged to pass two changes to the ACA that she wants. Collins said the changes will continue Obamacare subsidies for two more years and allow for a version of high-risk pools for people with pre-existing conditions, which she says will help keep policies affordable.

The Senator said there is also a pledge from the majority leader to help avoid Medicare budget cuts.

Democrats and organized labor were quick to criticize Collins' decision, saying passage of the tax plan will hurt low-income Mainers and "working families", and would only benefit the wealthy and corporations.

The Senate GOP plan also includes a significant cut in the corporate income tax. The House already passed its own tax cut plan several weeks ago. Those two plans will now go to a conference committee to negotiate a single package, then be put to final votes.