(Adds comments on reforms, election)
BUENOS AIRES, Aug 30 (Reuters) - Argentina's government will forecast economic growth of 3 percent and inflation of 12 percent in 2018 when it presents its budget bill in early September, Senate leader Federico Pinedo told Reuters on Wednesday.
In the 2017 budget, President Mauricio Macri's government had forecast 3.5 percent growth for 2017 and 2018. The new budget will forecast a fiscal deficit of 3.2 percent of gross domestic product, in line with the government's current forecast for next year and down from 4.2 percent expected in 2017.
"We will be moving towards a lower deficit, much less inflation and more growth," Pinedo, provisional Senate president and a member of Macri's "Let's Change" coalition, said in an interview.
"The government wants to be realistic and not put goals that it can't complete. It has goals that it could actually surpass," he said.
The budget bill will be presented to Congress before Sept. 15.
Macri took office in late 2015 promising to open Argentina's economy and pass reforms to promote economic growth and attract investment. Argentina emerged from recession in the second half of 2016 and the government expects growth of around 3 percent this year.
Macri is eyeing more reforms after mid-term congressional elections in October, and hopes to lower taxes before the end of the year. "Let's Change" does not have a majority in Congress and needs to negotiate with opposition parties to pass reforms.
"The agreements at the end of the year will be oriented towards how to make Argentina more productive, generating more employment and maintaining good wages," Pinedo said. "The tax load is very high in Argentina."
While investors have cheered Macri's reforms, many Argentines have felt the pinch of his austerity agenda including measures like an end to home heating gas subsidies. That makes former populist President Cristina Fernandez a tough contender for a Senate seat in Buenos Aires province.
Fernandez had some 20,000 more votes than Macri's ally Esteban Bullrich in an Aug. 13 primary vote, according to final results released this week, and Pinedo said he was confident Bullrich would triumph in October.
"I believe that we will win the province of Buenos Aires," he said.
"The election clearly shows that 'Let's Change' is representing the largest group in Argentina, a group that wants to leave behind decades of decadence." (Reporting by Nicolas Misculin; Writing by Caroline Stauffer; Editing by Chris Reese and Lisa Shumaker)