1973 Cancelled ETCC Races

The 1973 ETCC provisional calendar for 1973 included races at Estoril and Jarama that were both cancelled. I think the Estoril race may have been scheduled for July 8th (the GT race went ahead that day though possibly the ETCC race was cancelled due to beginning of the oil crisis, and/or political unrest that led to the Carnation Revolution the following Spring?). I cannot find a provisional date for the Jarama event or indeed a reason why it was cancelled. It's not mentioned on the late Frank de Jong's TCR site either - he's usually my "go-to' source. Can anyone cast some light please?

Dates now identified - Estoril was proposed for April 4th (the same day as the International Trophy) and Jarama was October 7th (clashing with the US GP). Still no line on the reason other than a generic "fuel crisis" - seems too simple.

The 1973 ETCC provisional calendar for 1973 included races at Estoril and Jarama that were both cancelled. I think the Estoril race may have been scheduled for July 8th (the GT race went ahead that day though possibly the ETCC race was cancelled due to beginning of the oil crisis, and/or political unrest that led to the Carnation Revolution the following Spring?). I cannot find a provisional date for the Jarama event or indeed a reason why it was cancelled. It's not mentioned on the late Frank de Jong's TCR site either - he's usually my "go-to' source. Can anyone cast some light please?

Nothing to do with the Carnation Revolution which happened one year later. In April 1973 the regime looked still reasonable stable. Also the oil crisis only started in October that year. 

More probably it was a cost-related issue as the national races foreseen to complement the "4 Hours of Estoril" still took place.