The ISP (Imposto sobre Produtos Petrolíferos e Energéticos) is Portugal's excise tax on petroleum and energy products, charged as a fixed amount per liter on petrol, diesel, and other fuels. It is one of the main components of fuel prices at the pump, alongside VAT and the carbon tax (Taxa de Carbono).

The government can adjust ISP rates — temporarily or permanently — to influence fuel prices. Rate cuts are a common policy tool to ease cost-of-living pressures on drivers and transport businesses, though they also reduce government revenue.

For consumers, the ISP is significant because even small changes in the per-liter rate translate into noticeable differences at the pump, particularly for diesel users and commercial transport operators.

Christine Lagarde is President of the European Central Bank since November 2019 and was Managing Director of the IMF from 2011 to 2019. Her decisions and public statements influence ECB monetary policy, which affects euro interest rates, mortgages and inflation across the euro area.