The engine, which is being jointly developed by RollsRoyce and General Electric under a $2.4 billion (£1.31 billion), was deemed too expensive by President George W Bush, despite pleas from Tony Blair.
But Republicans on the US tactical air subcommittee last week voted to restore $408 million (£222.9 million) for the engine to the Pentagon's 2007 budget.
GE said it was encouraged by the House action and hoped the Senate Armed Services Committee would follow suit when it marks up its defence spending bill this week, said spokesman Rick Kennedy.
GE officials have said that cancellation of the second engine would in effect knock the company out of the fighter engine business, which accounts for at least half of its $3.5 billion (£1.91 billion) a year military-engine work. n Dubai's Emirates airlines, which operates daily services from Birmingham, yesterday said it could place orders for as many as 100 mid-sized planes, double the number the company had previously said it was considering.
"If we get what we want, then we could go for a big order, even up to 100, why not?
"We need more aircraft," The Gulf News daily quoted Emirates president Tim Clark as saying.
An Emirates official confirmed Mr Clark's remarks.
Emirates had previously said it was considering a deal for 50 mid-sized planes and was in talks with Airbus and rival manufacturer Boeing.
Emirates is pushing manufacturers to reconfigure the aircraft to increase capacity and make them more fuel-efficient.
It is deciding between Boeing's 787 Dreamliner and Airbus's rival A350 for the order but has said it is in no hurry to make a decision.
Derby-based aero-engine manufacturer Rolls-Royce was in confident mood yesterday - predicting long-term growth despite the twin challenges of commodity price inflation and the continuing weakness of the US dollar.
Chief executive Sir John Rose told shareholders at the group's annual meeting in London that current trading was in line with expectations.
"We have recently made proposals to our employees in order to address the pension fund deficit," Sir John added. "The key points are that we are offering to inject £500 million in cash in return for agreement on certain measures.
"The proposals are intended to reduce the size and volatility of the deficit and include a move from defined benefit to defined contribution schemes for new employees. We would, however, maintain existing benefits for current scheme members.
"Looking to the future, our strong order book, long-term services revenue stream and our focus on operational performance underpin our expectations for 2006, of positive cash flow, before the impact of any additional cash injections to the pension schemes, and a continued growth in profits."
His comments came as Rolls-Royce landed a $200 million (£108 million) deal to supply 42 propulsion systems for the C-27J tactical military transport aircraft from Finmeccanica subsidiary Alenia Aeronautica.
Meanwhile, the US House of Representatives Arms Services Committee could approve measures which would restore some of the funding needed to design a second engine for the Lockheed Martin F-35 Joint Strike Fighter. ..SUPL: