LONDON: Sterling fell more than one percent against the dollar on Monday, as the greenback strengthened broadly and doubts grew over British Prime Minister Theresa May's ability to get the backing of the European Union and her own party for any Brexit deal.

On Monday, the British currency plunged to a 1-1/2 week low of $1.2841 as negative headlines over the last 48 hours punctured growing optimism last week that a deal was imminent.

"Headlines over the weekend suggest that's now less likely, and in any case, the crucial task of getting it approved by Parliament looks just as challenging as ever," ING strategists said in a note.

May has called off a special cabinet meeting on Brexit due to take place today, the Independent website reported, amid growing signs she would not get parliamentary backing for her proposed compromise with the EU.

There are also reports that more ministers were set to quit, following the resignation last week of transport minister Jo Johnson.

May's former education minister said parliament will vote down the prime minister's possible Brexit deal so voters should be given a new referendum.

Sterling's woes was compounded by a broad-based dollar rally with the greenback strengthening 0.8 percent against the euro  and 0.4 percent against the Australian dollar .

The latest drop in the value of sterling comes in the backdrop of rising short positions in the pound. Latest futures data showed net short positions registered their biggest weekly rise in 1-1/2 months to $4.6 billion.

However, a heavy slate of economic data this week might offer some support to battered sterling bulls. Wages, inflation and retail sales data are all due this week.