In a major relief to companies like Reliance Industries, the government is likely to restore a 7-year income tax holiday on oil and gas production as it was a sovereign commitment to companies investing in the nascent sector. But uncertainity continues over the same tax break being extended to refineries commissioning after April 1, 2009. Sources in the finance ministry said the Budget proposals for 2008-09 had actually intended only to introduce a sunset clause for 7-year income tax holiday for refineries commissioned after April 1, 2009.