Inflation is likely to go up to 15 per cent in the next two months with the full impact of fuel price hike reflecting in it coupled with the increase in consumption due to the upcoming festive season, Assocham said.
The chamber also said that consumer price based inflation too would overshoot 18 per cent in the same period.
"The full impact of rise in prices of petroleum products such as petrol, diesel and kerosene would begin its reflection from next two-three weeks...cost of transportation of goods would further go up and stroke inflation," Assocham Secretary General D S Rawat said.
Inflation rose to 10.55 per cent in June from 10.16 per cent in the previous month.
The Prime Minister's economic advisory panel has also expressed concerns over double-digit inflation.
The upcoming festival season would also drive the demand of almost every commodity and substantially fuel inflation rates, Rawat said.
Crude prices are not showing any downward movement while prices of metals like zinc, copper and aluminum are also soaring due to rising demand.
"All these factors would push up inflation even if state governments are able to manage movement of supplies," he said.
The chamber said that rains disrupting supplies of food and primary articles could also fuel inflation.
"(If the) supply chain process gets disrupted (due to heavy rains), it leads to shortages of supplies and fuels inflation," it said.
The chamber said that due to the high inflationary pressure, the RBI may further increase key policy rates.
The RBI has been tightening its monetary policy since February this year to control inflation. In its monetary review last month, it raised its short term lending and borrowing rates by 25 basis points each.