McLaren drivers Fernando Alonso and Stoffel Vandoorne's grid penalties at the Azerbaijan Grand Prix on Sunday have been extended to 40 and 30 respectively, the International Automobile Federation (FIA) said.

The FIA stewards said in a statement that twice Formula One world champion Alonso had another 25-place grid penalty added to his previous sanction of 15 grid places after changing his car's Honda engine for a seventh time this season.

Drivers are permitted to use a maximum of four engines per season.

In a separate statement, the FIA said Alonso's team mate Vandoorne has had his grid penalty extended to 30 places after the same offence.

Vandoorne's use of a seventh Turbo Charger (TC) and seventh Motor Generator Unit Heat during the third practice session means he drops 15 grid positions, added to the 15-place penalty he incurred earlier in the week.

The sanctions ensure that McLaren will occupy the back row in Sunday's race, regardless of their performance in qualification on Saturday.

The punishments are yet another embarrassing episode for the team as they seek to improve their efficiency, reliability and track performance.

Neither Alonso nor Vandoorne have taken any points during the opening seven races of the 2017 season.

"We'll have to start at the back of the grid anyway, so we'll take things smoothly in qualifying," Alonso told McLaren's official website (www.mclaren.com) after Friday's session.

"Today, we chose to concentrate on our long-run pace because we knew we'd be taking grid penalties for the race."

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.