Cape Town - Force India's 'best of the rest' position in the championship could be threatened this coming season by both Renault and McLaren, says Bob Fernley.
Although Force India achieved back-to-back P4s in the 2016 and 2017 seasons, the team was able to taken advantage of McLaren's fall from grace and Renault's rebuilding.
As such, with McLaren now on Renault engines and Renault putting in a strong finish to 2017, Fernley admits the pressure is on.
"Both Renault and McLaren look quite handy," he told Autosport.
"They are a significant threat and we need to take it seriously. We need to do quite a bit of work ourselves to make sure that we accommodate that.
"There will be no quarter given for those three cars. The three teams will be locked into a massive battle."
And in McLaren and Renault, Force India will also be going up against two teams with much bigger budgets with McLaren's believed to be double the size of the Silverstone-based team's.
"It'll always be difficult to compete against the bigger budgets, but saying that, we've done it for two years in a row so there's no reason why we can't do it for a third," Fernley added.