AUSTIN, Texas -- The good news Texas lawmakers will head back to work with on Tuesday is there's more money to spend. 

• Texas Legislature returns to work Tuesday
• Comptroller Glenn Hegar said a robust economy will give the Legislature more spending power

Texas Comptroller Glenn Hegar offered his estimate Monday, giving lawmakers nearly $9 billion more for the next budget. 

With talk of tackling school finance reform and slowing the growth of Texans' property tax bills, that is welcomed news. However, Hegar warned lawmakers about heightened economic uncertainty in the U.S. and globally.  

"Being that we are in the longest economic expansion in modern history, at some point we're not going to be," said Hegar.  

For example, recent falling oil prices may excite Texas drivers at the pump, but Dale Craymer with the Texas Tax Payers and Research Association said that costs the state. 

"A $1-drop in the price of oil probably costs the state treasury somewhere close to $100 million in foregone tax revenue," said Craymer.  

Lawmakers go in with the idea they will have about $119 billion to spend over the next two years, which is up nearly $9 billion from the last budget. The state's savings account known as the rainy day fund will have a record balance of $15 billion. 

"This is a significant amount of money and we need to have a very healthy discussion and vet out all the issues which is what the legislature is going to do, I have no doubt whatsoever," said Hegar.  

Lawmakers will debate whether to tap into the rainy day fund to pay for bills coming due from the last budget, including Hurricane Harvey recovery.

"There's more of a willingness to tap the rainy day fund for those one-time expenses," said Craymer.  

Advocates pushing for lawmakers to pump more money into public education are also saying lawmakers now have no excuse not to increase spending. 

"Five-billion would be enough for this current two years but then again, look at ways to raise new state revenue," said Eva DeLuna Castro.  

Balancing the budget is the only item lawmakers are constitutionally required to get done, but the budget battles could drag on for months.  The governor, lieutenant governor and other state lawmakers were quick to weigh in on the budget news. 

Most of them noted that it's a positive step toward being able to address school finance and property tax reform.