Britain warned Kremlin chief Vladimir Putin on Monday that the Russian economy would face sectoral sanctions unless Moscow granted full access to the Malaysia Airlines crash site and stopped stoking instability in Ukraine.
Britain says a Russian missile fired from Ukrainian territory controlled by Russian-backed rebels probably shot down Malaysia Airlines flight MH17 with the loss of 298 lives including 10 British nationals.
"We should be discussing going further, sectoral measures, tier three," a spokesman for British Prime Minister David Cameron told reporters.
"If Russia does not, in the coming period, take steps both in terms of the immediate response to the crash but also the very directly related issues around instability in eastern Ukraine, then we will be arguing that we have to go further."
Britain will argue hard at a European Union meeting of foreign ministers on Tuesday for further action on sanctions against Russia, the British premier's spokesman said.
The spokesman said Britain was also pushing for the immediate implementation of sanctions on Russian individuals and entities agreed by the EU last week.
Reporting by William James