By Abhishek Takle

SPA-FRANCORCHAMPS, Belgium, (Reuters) - Lewis Hamilton will start Sunday’s Belgian Formula One Grand Prix from near the back of the grid due to an engine-related penalty, but the championship leader is confident the setback will not halt his momentum.

The Mercedes driver is set to take a hefty penalty for exceeding his allowed allocation of engine components after early-season reliability woes left him short of parts.

“As far as I’m aware, we will be taking the penalty this weekend,” the Mercedes driver told reporters at the Spa-Francorchamps circuit on Thursday.

“I have no engines left.”

How many places he will drop on the grid, however, remains unclear with a team spokesman saying the Briton was expected to start at or very close to the back of the grid.

Drivers are limited to using a maximum of five power units, and the respective components that comprise them, over the course of a season.

Any breach is punished with a sliding scale of grid penalties while taking on a completely fresh power unit forces a driver to start at the very back of the grid.

Hamilton was long aware that he would have to drop places on the grid in either Belgium or at the next race in Italy, with both held on fast circuits that offer greater opportunities for overtaking.

But the penalty dents his hopes of becoming only the third driver in history to score a landmark 50th victory this weekend.

“In terms of winning, it’s going to be very, very hard,” said the triple world champion.

“But I’ll do everything I can.”

Hamilton leads team mate Nico Rosberg by 19 points in the standings, having closed out the opening half of the season with a streak of six wins from the last seven races.

The 31-year-old, who trailed Rosberg by 43 points after May’s Spanish Grand Prix, scored the last four of those in succession and on Thursday appeared unfazed by the prospect of the penalty halting his charge.

“That (penalty) will come into play for sure,” said Hamilton.

“Otherwise, beyond that … I think I will be able to continue with the momentum that I had before the break.”

(Editing by Ed Osmond)