The Greens will focus heavily on five key seats ahead of the general election on 8 June, a senior party source confirmed to IBTimes UK on Thursday 20 April.

Molly Scott Cato, who represents the South West of England in the EU Parliament, will fight for Labour-held Bristol West as Caroline Lucas, the sole Green MP, campaigns to keep her Brighton Pavilion seat.

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Elsewhere, the left-wingers will also target the Labour safe seat of Sheffield Central, Conservative semi-marginal the Isle of Wight and Tory-held Bath.

"The Greens are embarking on our boldest campaign ever," the source told IBTimes UK.

"Of course the top priority will be building on Caroline Lucas' solid majority but we're going to be going much further than that.

"For a start that means turning the monumental swing in our favour in Bristol West last time into a seat in parliament for Molly Scott Cato."

The comments come just a day after Lucas and Jonathan Bartley called for discussions with Liberal Democrat leader Tim Farron and Labour's Jeremy Corbyn in a bid to form an anti-Tory alliance.

The latest opinion polls from ICM, YouGov and ComRes had the Greens on 4%, just above the party's 3.8% share of the vote at the 2015 general election.

Bristol West

Current MP: Labour's Thangam Debbonaire

Majority: 5,673

2015 general election result:

Labour: 22,900 (35.7%)

Green: 17,227 (26.8%)

Lib Dem: 12,103 (18.8%)

Conservative: 9,752 (15.2%)

Ukip: 1,940 (3%)

Brighton Pavilion

Current MP: Greens' Caroline Lucas

Majority: 7,967

2015 general election result:

Green: 22,871 (41.8%)

Labour: 14,904 (27.3%)

Conservative: 12,448 (22.8%)

Lib Dem: 1,525 (2.8%)

Ukip: 2,724 (5%)

Independent: 116 (0.2%)

Sheffield Central

Current MP: Labour's Paul Blomfield

Majority: 17,309

2015 general election result:

Labour: 24,308 (55%)

Green: 6,999 (15.8%)

Conservative: 4,917 (11.1%)

Lib Dem: 4,278 (9.7%)

Ukip: 3,296 (7.5%)

Isle of Wight

Current MP: Conservative Andrew Turner

Majority: 13,703

2015 general election result:

Conservative: 28,591 (40.7%)

Ukip: 14,888 (21.2%)

Green: 9,404 (13.4%)

Labour: 8,984 (12.8%)

Lib Dem: 5,235 (7.4%)

Bath

Current MP: Conservative Ben Howlett

Majority: 3,833

2015 general election result:

Conservative: 17,833 (37.8%)

Lib Dem: 14,000 (29.7%)

Labour: 6,216 (13.2%)

Green: 5,634 (11.9%)

Ukip: 2,922 (6.2%)

[Source: UK Polling Report]